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 A230978 #12 May 06 2024 01:43:59 %S A230978 0,2,6,14,25,37,49,67,87,103,125,157,204,240,268,306,342,358,382,422, %T A230978 478,548,618,688,772,832,898,982,1101,1185,1245,1323,1391,1407,1431, %U A230978 1471,1527,1597,1669,1751,1863,1971,2099,2235,2419,2581,2739,2879,3027,3107,3182,3298,3458,3660,3876,4080 %N A230978 a(n) = (A220500(n) - 1)/2. %H A230978 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 A230978 <a href="/index/To#toothpick">Index entries for sequences related to toothpick sequences</a>. %Y A230978 Cf. A139250, A220500, A220520, A220522, A220526. %K A230978 nonn %O A230978 1,2 %A A230978 _Omar E. Pol_, Nov 30 2013 %E A230978 More terms added using the data at A220500 by _Amiram Eldar_, May 06 2024