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 A036655 #6 Jul 08 2025 21:53:13 %S A036655 1,2,2,6,2,18,2,46,14,126,2,454,2,1266,134,4222,2,14202,2,46406,1274, %T A036655 155502,2,531790,122,1792810,13802,6126334,2,21032794,2,72121854, %U A036655 155510,248396798,1382,857944150,2,2964896882,1792818,10269600622 %N A036655 Numbers d_n used in recurrence for series-parallel numbers. %D A036655 J. Riordan, An Introduction to Combinatorial Analysis, foot of p. 141. %F A036655 G.f.: S'*(1-S)/(1+S), where S = g.f. for A000084. %K A036655 nonn,easy %O A036655 0,2 %A A036655 _N. J. A. Sloane_