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 A213641 #7 Nov 03 2012 22:16:53
%S A213641 1,1,4,33,408,6760,140880,3543120,104469120,3535037856,135053291520,
%T A213641 5750579640960,270067321117440,13868724577593600,773138898730598400,
%U A213641 46500352460941579200,3001412657729335449600,206946807350480534937600,15180752044039172426035200
%N A213641 E.g.f. satisfies: A(x) = 1 - log(1 - x^2*A(x)^2) / x.
%F A213641 E.g.f. satisfies: A(x + log(1-x^2)) = x/(x + log(1-x^2)).
%F A213641 E.g.f.: A(x) = (1/x)*Series_Reversion(x + log(1-x^2)).
%F A213641 a(n) = A213640(n+1)/(n+1).
%e A213641 E.g.f.: A(x) = 1 + x + 4*x^2/2! + 33*x^3/3! + 408*x^4/4! + 6760*x^5/5! +...
%e A213641 Related expansions:
%e A213641 A(x)^2 = 1 + 2*x + 10*x^2/2! + 90*x^3/3! + 1176*x^4/4! + 20240*x^5/5! +...
%e A213641 -log(1 - x^2*A(x)^2)/x = x + 4*x^2/2! + 33*x^3/3! + 408*x^4/4! +...
%e A213641 A(x + log(1-x^2)) = 1 + x + 2*x^2/2! + 9*x^3/3! + 48*x^4/4! + 340*x^5/5! +...
%o A213641 (PARI) {a(n)=n!*polcoeff((1/x)*serreverse(x+log(1-x^2 +x^2*O(x^n))), n)}
%o A213641 for(n=0,25,print1(a(n),", "))
%Y A213641 Cf. A213640, A218653, A200320.
%K A213641 nonn
%O A213641 0,3
%A A213641 _Paul D. Hanna_, Jun 17 2012