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 A151710 #11 Feb 24 2021 02:48:18 %S A151710 1,3,3,9,3,9,9,21,3,9,9,21,15,21,27,51,3,9,9,21,15,21,27,51,21,21,27, %T A151710 51 %N A151710 First differences of A160715. %C A151710 Number of Y-toothpick added at n-th stage to the structure of A160715. %C A151710 Similar to A160121. [From _Omar E. Pol_, May 29 2010] %H A151710 David Applegate, Omar E. Pol and N. J. A. Sloane, <a href="/A000695/a000695_1.pdf">The Toothpick Sequence and Other Sequences from Cellular Automata</a>, Congressus Numerantium, Vol. 206 (2010), 157-191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n-1)-1) for n >= 2.] %H A151710 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> %e A151710 Contribution from _Omar E. Pol_, Dec 18 2012 (Start): %e A151710 Written as an irregular triangle begins: %e A151710 1; %e A151710 3; %e A151710 3, 9; %e A151710 3, 9, 9, 21; %e A151710 3, 9, 9, 21, 15, 21, 27, 51; %e A151710 3, 9, 9, 21, 15, 21, 27, 51, 21, 21, 27, 51,... %e A151710 (End) %Y A151710 Cf. A000225, A006516, A139250, A160120. %Y A151710 Cf. A048883, A139251, A151837, A160121. %K A151710 more,nonn %O A151710 1,2 %A A151710 _Omar E. Pol_, Jun 02 2009 %E A151710 More terms from _Omar E. Pol_, May 29 2010