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 A052135 #14 Feb 12 2014 22:20:46
%S A052135 1,18,1080,408240,29393280,215550720,648499737600,953294614272000,
%T A052135 2333665215737856000,7183021534041120768000,232066849561328517120000,
%U A052135 723095875143672151080960000,74189636789740762700906496000000
%N A052135 Denominators of coefficients in function a(x) such that a(a(a(x))) = sin x.
%C A052135 Also denominators of coefficients in function a(x) such that a(a(a(x))) = sinh x.
%D A052135 W. C. Yang, Composition equations, preprint, 1999.
%t A052135 n = 13; m = 2 n - 1 (* m = maximal degree *); a[x_] = Sum[c[k] x^k, {k, 1, m, 2}] ; coes = DeleteCases[ CoefficientList[Series[a @ a @ a @ x - Sin[x], {x, 0, m}], x] // Rest , 0]; Do[s[k] = Solve[coes[[1]] == 0] // First; coes = coes /. s[k] // Rest, {k, 1, n}]
%t A052135 (CoefficientList[a[x] /. Flatten @ Array[s, n], x] // Denominator // Partition[#, 2] &)[[All, 2]]
%t A052135 (* _Jean-François Alcover_, May 04 2011 *)
%Y A052135 Cf. A052132, A052134. See also A048602, A048603, etc.
%K A052135 nonn,frac,easy,nice
%O A052135 0,2
%A A052135 _N. J. A. Sloane_, Jan 22 2000
%E A052135 More terms from _Vladeta Jovovic_, Jul 16 2002