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 A000163 M1852 N0732 #19 Feb 09 2016 07:39:08 %S A000163 2,8,34,136,538,2080,7970,30224,113874,426520,1590338,5906640, %T A000163 21866794,80725280,297292610,1092539736,4007553922,14675748416, %U A000163 53663197698,195962433328,714734393378,2603994002280,9477643739746,34463730424720 %N A000163 Series-parallel numbers. %D A000163 J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 142. %D A000163 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). %D A000163 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A000163 Sean A. Irvine, <a href="/A000163/b000163.txt">Table of n, a(n) for n = 2..500</a> %F A000163 G.f.: 2*(1+S)/(1-S)^3, where S = g.f. for A000084. [_Sean A. Irvine_, Oct 14 2009] %t A000163 n = 25; s = 1/(1 - x) + O[x]^(n + 1); Do[s = s/(1 - x^k)^Coefficient[s, x^k] + O[x]^(n + 1), {k, 2, n}] ; S = s - 1; CoefficientList[2*(1 + S)/(1 - S)^3 + O[x]^n, x] (* _Jean-François Alcover_, Feb 09 2016 *) %K A000163 nonn %O A000163 2,1 %A A000163 _N. J. A. Sloane_ %E A000163 More terms from _Sean A. Irvine_, Oct 14 2009