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 A281427 #6 Mar 01 2017 10:54:40
%S A281427 1,5,145,10325,1357825,284963525,87274812625,36716097543125,
%T A281427 20309401097610625,14290053364475013125,12462411363013047060625,
%U A281427 13192751210140624100103125,16663953549286540157926890625,24756557919279291667433199453125,42733906625427778939437818074140625,84814104213422372894487597292655703125
%N A281427 E.g.f. S(x) satisfies: S(x) = Integral (1 + S(x)^2)^(5/2) dx.
%F A281427 C(x)^2 - S(x)^2 = 1 and S'(x) = C(x)^5, where C(x) is described by A281428.
%t A281427 a[n_] := Module[{S = x, C = 1, C5, SC4}, For[i = 1, i <= n, i++, C5 = C^5 + x*O[x]^(2n) // Normal; S = Integrate[C5, x]; SC4 = S*C^4 + O[x]^(2n-1) // Normal; C = 1 + Integrate[SC4, x] ]; (2n-1)!*Coefficient[S, x, 2n-1]]; Array[a, 16] (* _Jean-François Alcover_, Mar 01 2017, translated from Pari *)
%o A281427 (PARI) {a(n) = my(S=x, C=1); for(i=1, n, S = intformal( C^5 +x*O(x^(2*n))); C = 1 + intformal( S*C^4 ) ); (2*n-1)!*polcoeff(S, 2*n-1)}
%o A281427 for(n=1, 30, print1(a(n), ", "))
%K A281427 nonn
%O A281427 1,2
%A A281427 _Paul D. Hanna_, Jan 21 2017