This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A100729 #17 Aug 12 2015 23:41:20 %S A100729 32,26,444,1628,5906,80,126960,380882,2097152,1047588,148814,8951040, %T A100729 5406720,242,127842440,11419626400,12885001946,160159528116, %U A100729 687195466408,6390911336402,11728121233408,20104735604736 %N A100729 Period of the first difference of Ulam 1-additive sequence U(2,2n+1). %C A100729 It was proved by Akeran that a(2^k-1) = 3^(k+1) - 1. %C A100729 Note that a(n)=2^(2n+1) as soon as A100730(n)=2^(2n+3)-2, that happens for n=(m-2)/2 with m>=6 being an even element of A073639. %H A100729 Max Alekseyev, <a href="/A100729/b100729.txt">Table of n, a(n) for n = 2..31</a> %H A100729 M. Akeran, <a href="/A003668/a003668.pdf">On some 1-additive sequences</a> %H A100729 J. Cassaigne and S. R. Finch, <a href="http://www.emis.de/journals/EM/expmath/volumes/4/4.html">A class of 1-additive sequences and additive recurrences</a> %H A100729 S. R. Finch, <a href="http://www.emis.de/journals/EM/expmath/volumes/1/1.html">Patterns in 1-additive sequences</a>, Experimental Mathematics 1 (1992), 57-63. %e A100729 For k=2, we have a(3)=3^3-1=26. %Y A100729 Cf. A100730 for the fundamental difference, A001857 for U(2, 3), A007300 for U(2, 5), A003668 for U(2, 7). %Y A100729 Cf. also A006844. %K A100729 nonn %O A100729 2,1 %A A100729 _Ralf Stephan_, Dec 03 2004 %E A100729 a(3) corrected from 25 to 26 by _Hugo van der Sanden_ and Bertram Felgenhauer (int-e(AT)gmx.de), Nov 11 2007 %E A100729 More terms from Balakrishnan V (balaji.iitm1(AT)gmail.com), Nov 15 2007 %E A100729 a(21..31) and b-file from _Max Alekseyev_, Dec 01 2007