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 A255049 #30 Feb 19 2015 00:11:48 %S A255049 0,2,2,6,2,6,10,14,2,6,10,14,10,22,34,30,2,6,10,14,10,22,34,30,10,22, %T A255049 34,38,42,78,98,62,2,6,10,14,10,22,34,30,10,22,34,38,42,78,98,62,10, %U A255049 22,34,38,42,78,98,70,42,78,106,118,162,254,258,126,2,6,10,14,10 %N A255049 a(n) = 2*A160552(n). %H A255049 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 A255049 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a> %F A255049 It appears that a(n) = A169708(n)/2, n >= 1. %e A255049 Written as an irregular triangle in which row lengths are the terms of A011782 the sequence begins: %e A255049 0; %e A255049 2; %e A255049 2,6; %e A255049 2,6,10,14; %e A255049 2,6,10,14,10,22,34,30; %e A255049 2,6,10,14,10,22,34,30,10,22,34,38,42,78,98,62; %e A255049 2,6,10,14,10,22,34,30,10,22,34,38,42,78,98,62,10,22,34,38,42,78,98,70,42,78,106,118,162,254,258,126; %e A255049 It appears that row sums give 0 together with A004171, (see also A081294). %e A255049 It appears that right border gives the nonnegative terms of A000918, (see also A095121). %Y A255049 Cf. A000918, A004171, A081294, A095121, A139250, A160164, A160552, A169707, A169708, A187220. %K A255049 nonn,tabf %O A255049 0,2 %A A255049 _Omar E. Pol_, Feb 13 2015 %E A255049 Edited by _Omar E. Pol_, Feb 18 2015