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 A169780 #12 Mar 07 2013 20:36:05 %S A169780 0,1,3,5,9,11,15,21,29,31,35,41,51,61,69,83,99,101,105,111,121,131, %T A169780 141,159,185,203,211,225,249,277,297,329,361,363,367,373,383,393,403, %U A169780 421,447,465,475,493,523,561,595,637,695,729,737,751,775,803,831,875,943,1003,1031 %N A169780 Total number of ON cells after n-th stage in one-sixth slice of hexagonal CA defined in A151723 (including both boundaries). %C A169780 Partial sums of A170905. %H A169780 N. J. A. Sloane, <a href="/A169780/b169780.txt">Table of n, a(n) for n = 0..1025</a> %H A169780 N. J. A. Sloane, <a href="/wiki/Catalog_of_Toothpick_and_CA_Sequences_in_OEIS">Catalog of Toothpick and Cellular Automata Sequences in the OEIS</a> %H A169780 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a> %F A169780 a(n) = n + (A151723(n) - 1)/6, n >= 1. - _Omar E. Pol_, Mar 06 2013 %Y A169780 Cf. A151723, A169779, A169781. %K A169780 nonn %O A169780 0,3 %A A169780 _N. J. A. Sloane_, May 11 2010