Recent papers

• Brady Haran and N. J. A. Sloane, Problems with Powers of Two, Youtube Numberphile Video, Sep 21 2022; STOP PRESS: Postscript to Problems with Powers of Two, Sep 21 2022. See A352178 for the latest results.
• N. J. A. Sloane, New Sequence Problems and Solutions from 2022, Talk in Doron Zeilberger's Experimental Math Seminar at Rutgers University, Sept. 15, 2022; Youtube video, Slides
• Michael De Vlieger, Thomas Scheuerle, R\'{e}my Sigrist, N. J. A. Sloane, and Walter Trump, The Binary Two-Up Sequence, arXiv:2209.04108, Sep 11 2022.
• Blog: The Two-Up Sequence A090252, June 13 2022. I started a blog about a very interesting "Lexicographically Earliest" sequence A090252 that might be solvable with a collective effort. Many conjectures but few theorems. Please help!
• N. J. A. Sloane, The On-Line Encyclopedia of Integer Sequences: An illustrated guide with many unsolved problems, Guest Lecture given in Doron Zeilberger's Experimental Mathematics Math640 Class, Rutgers University, Spring Semester, Apr 28 2022: Video, Slides.
• Max A. Alekseyev and N. J. A. Sloane, On Kaprekar's Junction Numbers, Preprint, March 2022.
• Brady Haran and N. J. A. Sloane, Stones on an Infinite Chessboard, Numberphile video, January 2022.
• Brady Haran and N. J. A. Sloane, Most Wanted Prime, Numberphile video, December 2021.
• N. J. A. Sloane, Lovely New Problems From the Past Months. Talk in Doron Zeilberger's Experimental Math Seminar at Rutgers University, Sept. 9, 2021; Video, Slides
• N. J. A. Sloane, The OEIS: A Fingerprint File for Mathematics, article for "Early Careers" section of Notices of Amer. Math. Soc., 68:9 (October 2021), 1515-1516.
• My current project (with Omar Pol and Hartmut Hoft) involves an object that fits in a corner, technically an encoignure. I wrote the following poem to show how to pronounce it.

  Bad Furniture
  
  The wardrobe has lost a lobe,
  The blender has gone on a bender,
  The pouf is rather uncouth,
  The armoire is not for moi,
  The icebox is full of rocks,
  The credenza has influenza,
  And worst of all,
  The encoignure is full of manure.
  

• Lars Blomberg, Scott R. Shannon, and N. J. A. Sloane, Graphical Enumeration and Stained Glass Windows, 1: Rectangular Grids, Preprint, revised May 21 2021. To appear in INTEGERS.
• Lars Blomberg, Scott R. Shannon, and N. J. A. Sloane, Graphical Enumeration and Stained Glass Windows, Additional Illustrations for Part 1, Rectangular Grids, Preprint, May 24 2021.
• M. Alekseyev, J. S. Myers, R. Schroeppel, S. R. Shannon, N. J. A. Sloane, and P. Zimmermann, Three Cousins of Recaman's Sequence, New version, May 29 2021, accepted for publication in Fibonacci Quarterly.
• F. Michel Dekking, Jeffrey Shallit, and N. J. A. Sloane, Queens in exile: non-attacking queens on infinite chess boards, Electronic J. Combin., 27:1 (2020), #P1.52.
• Eric Angelini, Lars Blomberg, Charlie Neder, Remy Sigrist, and N. J. A. Sloane, "Choix de Bruxelles": A New Operation on Positive Integers, arXiv:1902.01444, Feb 2019; Fibonacci Quarterly, 57:3 (2019), 195-200.
• N. J. A. Sloane, The On-Line Encyclopedia of Integer Sequences, Notices, Amer. Math. Soc., 65 (No. 9, Oct. 2018), 1062-1074.
• C. Goodman-Strauss and N. J. A. Sloane, A Coloring Book Approach to Finding Coordination Sequences, Acta Crystallographica Section A: Foundations and Advances, 2019, Volume A75, pages 121-134. Also on my home page. Also arXiv:1803.08530. [Last revised Jan 29 2019]
• Moa Apagodu, David Applegate, N. J. A. Sloane, Doron Zeilberger, Analysis of the Gift Exchange Problem, 2017. Also arXiv:1701.08394, although the version on my home page may be more up-to-date. [Last revised Jan 30 2017]
• Shalosh B. Ekhad, N. J. A. Sloane, and Doron Zeilberger, Automated Proofs (or Disproofs) of Linear Recurrences Satisfied by Pisot Sequences, 2016. Also arXiv:1609.05570, although the version on my home page may be more up-to-date. [Last revised Sep 27 2016]
• Margaret Wertheim, The Fax Numbers of the Beast, and Other Mathematical Sports: An Interview with Neil Sloane, Cabinet Magazine, Issue 57, Spring 2015, pages 48-54.
• Siobhan Roberts, How to Build a Search Engine for Mathematics: The surprising power of Neil Sloane's Encyclopedia of Integer Sequences, Nautilus Magazine, Issue 29, Chapter 4, Oct 22 2015.
• Featured in Slashdot on August 7 2015.
• Erica Klarreich, The Connoisseur of Number Sequences, Quanta Magazine, August 6 2015.
• May 2015: Elected Fellow of The Learned Society of Wales (FLSW)
• Shalosh B. Ekhad, N. J. A. Sloane, and Doron Zeilberger, Odd-Rule Cellular Automata on the Square Grid, 2015. Also arXiv:1503.04249, although the version on my home page may be more up-to-date. [Last revised Mar 20 2015]
• Shalosh B. Ekhad, N. J. A. Sloane, and Doron Zeilberger, A Meta-Algorithm for Creating Fast Algorithms for Counting ON Cells in Odd-Rule Cellular Automata, 2015. Also arXiv:1503.01796, although the version on my home page may be more up-to-date. See also the accompanying Maple package. [Last revised Mar 05, 2015.]
• N. J. A. Sloane, On the Number of ON Cells in Cellular Automata, submitted to Ron Graham Festschrift, 2015. Also arXiv:1503.01168, although the version on my home page may be more up-to-date. [Last revised Mar 05, 2015.]
• David L. Applegate, Hans Havermann, Bob Selcoe, Vladimir Shevelev, N. J. A. Sloane, and Reinhard Zumkeller, The Yellowstone Permutation, Journal of Integer Sequences, Vol. 18 (2015), Article 15.6.7; also arXiv:1501.01669 (JIS, arXiv, on my home page).
• Poster I created to celebrate reaching 250,000 sequences; key to the poster.
• OEIS-50 Conference. On October 9-10 2014 there was a conference at DIMACS, Rutgers University, to celebrate the 50th birthday of the OEIS, reaching 250,000 sequences, and my 75th birthday. Videos of the talks can be seen here
• N. J. A. Sloane, A Note on Modular Partitions and Necklaces; Preprint, 2014 (mentioned in A047996 and A241926). [May 06 2014]
• Claude Elwood Shannon: Miscellaneous Writings, edited by N. J. A. Sloane and A. D. Wyner, 1993, Deposited in The Library of Congress, The British Library, and the libraries of M.I.T., Cornell, Univ. Mich. and AT&T Bell Laboratories. October 15 2013: I have placed a copy on the Internet Archive - see archive.org/details/ShannonMiscellaneousWritings
• N. J. A. Sloane, 2178 And All That, Fibonacci Quarterly, 52 (2014), 99-120. Also arXiv:1307.0453, although the version on my home page may be more up-to-date.
• N. J. A. Sloane, Recent and Noteworthy Sequences in the OEIS. [Dec. 18, 2012]
• N. J. A. Sloane, Recent and Noteworthy Sequences in the OEIS: The Illustrations. [Dec. 18, 2012]
• B. Chaffin, J. P. Linderman, N. J. A. Sloane and A. R. Wilks, On Curling Numbers of Integer Sequences. [Dec. 25, 2012; Mar 12 2013]
• N. J. A. Sloane, The On-Line Encyclopedia of Integer Sequences, Proceedings Fifteenth Conference on Fibonacci Numbers, Eger, Hungary, June 2012, Annales Mathematicae et Informaticae, 41 (2013) pp. 219-234.
• Susanna Cuyler and N. J. A. Sloane, A Simple and Easily-Remembered Method for Solving the Rubik Cube, 2012. (An informal guide for distribution to friends.)
• D. Applegate, M. LeBrun, N. J. A. Sloane, Dismal Arithmetic, J. Int. Seq., 14 (2011), #11.9.8.
• D. Applegate, M. LeBrun, N. J. A. Sloane, Carryless Arithmetic, College Math. J., Vol. 43 (No. 1, 2012), pp. 43-50 (Special issue in honor of Martin Gardner), received 2013 George Polya Award from MAA; also arXiv:1008.4633.
• N. J. A. Sloane, V. A. Vaishampayan, S. I. R. Costa, A Note on Projecting the Cubic Lattice, Discr. Comput. Geom., 46 (No. 3, 2011), 472-478.
• D. Applegate, O. E. Pol, N. J. A. Sloane, The Toothpick Sequence and Other Sequences from Cellular Automata, Congress. Numer., 206 (2010), 157-191.
• D. Applegate, N. J. A. Sloane, The Gift Exchange Problem, arXiv:0907.0513, slightly later version with typo corrected.
• Eight Hateful Sequences, paper for the 8th Gathering for Gardner, revised Sept. 11, 2013 [old version: arXiv:0805.2128].
• N. J. A. Sloane, V. A. Vaishampayan, Generalizations of Schöbi's Tetrahedral Dissection, Discr. Comput. Geom., 41 (No. 2, 2009), 232-248; arXiv:0710.3857.
• C. Tian, V. A. Vaishampayan, N. J. A. Sloane, Constant Weight Codes: A Geometric Approach Based on Dissections, IEEE Trans. Inform. Theory, 55, (No. 3, 2009), 1051-1060; arXiv:0706.1217.
• Seven Staggering Sequences, in Homage to a Pied Puzzler, E. Pegg Jr. et al. (eds.), A. K. Peters, Wellesley, MA, 2009, pp. 93-110; arXiv:0912.2394.

Other recent highlights

• The OEIS appears (under 1973) in WolframAlpha's Timeline of Systematic Data and the Development of Computable Knowledge, which extends from cave paintings to the present day. [Oct 14 2011]
• Nov 11 2010: The new version of the OEIS is launched! For almost two years now, I have been trying to convert the On-Line Encyclopedia of Integer Sequences (OEIS) to a version that will run independently of me, and to find a permanent home for it, not on my home page. The first step was to set up a non-profit foundation to own, maintain and collect funds to support the OEIS: this was completed in 2009 - see The OEIS Foundation web site.

  The second step was to set up a version of the OEIS which would run autonomously on a commercial web site, operating as a moderated wiki, and controlled by a board of editors. Unfortunately, 18 months ago we discovered that the standard mediawiki software was incapable of handling the kind of queries that the OEIS generates. This problem seemed unsurmountable, and I had almost given up hope that it would ever be solved.

  But thanks to the enormous efforts of Russ Cox, who has completely rewritten all the OEIS software, the new OEIS was launched on Nov 11 2010. David Applegate has also been of great help in getting the new system working. At the time of the launch, the OEIS contained 180284 sequences. This means that after 46 years, I no longer have to process every single contribution to the database. Thank you, Russ and Dave: you have saved the OEIS!

  The URL for the new OEIS is oeis.org. I recommend that before using it, you first register at oeis.org/wiki. When you get issued a password, go to the main page and login with the same user name and password.

  Now when you look at a sequence, you will see "history" and "edit" buttons next to the "graph" and "listen" buttons. The "edit" button lets you edit the sequence. To submit a new sequence, use the "Submit new seq." link at the bottom of any sequence page. All contributions will be reviewed by the editors (if you would like to help by becoming an editor, let me know - we need more editors!).

• The OEIS Movie! To celebrate the launching of the OEIS Foundation, Tony Noe has made a movie showing the first 1000 terms of 1000 sequences, with soundtrack from Recaman's sequence A005132. The best way to watch it is to first download the file from Tony's web site, http://www.sspectra.com/math/OEISMovie.mov and then play it with QuickTimePlayer 7.
• The list of works that reference the OEIS is continually being updated. As of June 2015 there are over 4200 citations.

Tables

• OEIS
• Lattice catalogue
• Spherical codes (packings)
• Spherical codes (packings, coverings and max volume arrangements with icosahedral symmetry)
• Spherical codes (coverings)
• Spherical codes (t-designs)
• Spherical codes (minimal potential energy arrangements)
• Spherical codes (maximal volume arrangements)
• Packings of lines, planes etc.: packings in Grassmannian space
• Minimal-energy clusters of hard spheres
• Minimal Lennard-Jones potential clusters of soft spheres
• Hadamard matrices
• Orthogonal Arrays:
  (a) Parameters of arrays with up to 100 runs
  (b) Library of explicit arrays
  (c) The book.

Papers and Books Grouped by Subject: (Most of these pages need to be updated.)

• coding theory (see also covering radius of codes and codes over Z4),
• sphere packing, lattices and quadratic forms
• packing lines, planes, etc.: packings in Grassmannian spaces,
• spherical codes and designs,
• quantizing,
• geometry,
• combinatorics,
• designs (including experimental designs) (see also Gosset),
• integer sequences,
• group theory,
• graph theory,
• spectroscopy,
• crystallography,
• cryptography,
• rock climbing