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 A201628 #9 Jul 07 2012 19:03:55 %S A201628 1,1,4,31,360,5601,109568,2586151,71555200,2271961825,81441188352, %T A201628 3253620672303,143361363439616,6907049546879041,361245668908466176, %U A201628 20383791705206338807,1234336634416972726272,79843983527411321710401,5494767253686351671459840,400863405346004202504321343 %N A201628 E.g.f. satisfies: A(x) = 1/(1 - sinh(x*A(x))). %C A201628 The function 1/(1-sinh(x)) is the e.g.f. of A006154, where A006154(n) is the number of labeled ordered partitions of an n-set into odd parts. %F A201628 E.g.f. A(x) satisfies: A( x*(1 - sinh(x)) ) = 1/(1 - sinh(x)). %F A201628 E.g.f.: (1/x)*Series_Reversion( x*(1 - sinh(x)) ). %F A201628 a(n) = [x^n] 1/(1 - sinh(x))^(n+1) / (n+1). %F A201628 a(n) = A214223(n+1)/(n+1). %e A201628 E.g.f.: A(x) = 1 + x + 4*x^2/2! + 31*x^3/3! + 360*x^4/4! + 5601*x^5/5! +... %e A201628 The coefficients in initial powers of G(x) = 1/(1 - sinh(x)) begin: %e A201628 G^1: [(1), 1, 2, 7, 32, 181, 1232, 9787, 88832, ..., A006154(n), ...]; %e A201628 G^2: [1,(2), 6, 26, 144, 962, 7536, 67706, ...]; %e A201628 G^3: [1, 3,(12), 63, 408, 3123, 27552, 275103, ...]; %e A201628 G^4: [1, 4, 20,(124), 920, 7924, 77600, 850924, ...]; %e A201628 G^5: [1, 5, 30, 215,(1800), 17225, 185280, 2211515, ...]; %e A201628 G^6: [1, 6, 42, 342, 3192,(33606), 393792, 5080662, ...]; %e A201628 G^7: [1, 7, 56, 511, 5264, 60487, (766976), 10634911, ...]; %e A201628 G^8: [1, 8, 72, 728, 8208, 102248, 1395072,(20689208), ...]; ... %e A201628 where coefficients in parenthesis form initial terms of this sequence: %e A201628 [1/1, 2/2, 12/3, 124/4, 1800/5, 33606/6, 766976/7, 20689208/8, ...]. %o A201628 (PARI) {a(n)=n!*polcoeff(1/x*serreverse(x*(1-sinh(x+x^2*O(x^n)))),n)} %o A201628 (PARI) {a(n)=n!*polcoeff(1/(1 - sinh(x+x*O(x^n)))^(n+1)/(n+1), n)} %Y A201628 Cf. A214223, A201627, A201595, A006154. %K A201628 nonn %O A201628 0,3 %A A201628 _Paul D. Hanna_, Dec 03 2011