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 A281431 #6 Mar 01 2017 10:55:51
%S A281431 1,6,216,19296,3200256,849678336,329902212096,176210323070976,
%T A281431 123889924672782336,110895584511900450816,123119226530619884568576,
%U A281431 166015794146482719037587456,267231655288799665792971964416,506138971421813256899173596266496,1114219301421887004276203102410899456,2821068813384522963411318522740301889536,8139956209849296948206537756832040061239296
%N A281431 E.g.f. S(x) satisfies: S(x) = Integral (1 + S(x)^2)^3 dx.
%F A281431 C(x)^2 - S(x)^2 = 1 and S'(x) = C(x)^6, where C(x) is described by A281432.
%t A281431 terms = 20; max = 2 terms; se = (1/8)*((x*(5+3x^2))/(1+x^2)^2+3*ArcTan[x]) +O[x]^max; coes = CoefficientList[InverseSeries[se, x], x]*Range[0, max-1 ]!; Partition[coes, 2][[All, 2]] (* _Jean-François Alcover_, Mar 01 2017 *)
%o A281431 (PARI) {a(n) = my(S=x, C=1); for(i=1, n, S = intformal( C^6 +x*O(x^(2*n))); C = 1 + intformal( S*C^5 ) ); (2*n-1)!*polcoeff(S, 2*n-1)}
%o A281431 for(n=1, 30, print1(a(n), ", "))
%K A281431 nonn
%O A281431 1,2
%A A281431 _Paul D. Hanna_, Jan 21 2017