cp's OEIS Frontend

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.

A187546 Stirling transform (of the first kind, with signs) of the central Lah numbers (A187535).

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%I A187546 #21 Apr 10 2018 10:19:21
%S A187546 1,2,34,1096,51984,3262488,254943384,23853046656,2600024557248,
%T A187546 323588157732096,45276442446814656,7035574740347812800,
%U A187546 1202158966644148296000,224022356544364922931840,45215509996613004825121920
%N A187546 Stirling transform (of the first kind, with signs) of the central Lah numbers (A187535).
%H A187546 Vincenzo Librandi, <a href="/A187546/b187546.txt">Table of n, a(n) for n = 0..200</a>
%F A187546 a(n) = sum((-1)^(n-k)*s(n,k)*L(k), k=0..n), where s(n,k) are the (signless) Stirling numbers of the first kind and L(n) are the central Lah numbers.
%F A187546 E.g.f.: 1/2 + 1/Pi*K(16*log(1+x)), where K(z) is the elliptic integral of the first kind (defined as in Mathematica).
%F A187546 a(n) ~ n! / (2*Pi*n * (exp(1/16) - 1)^n). - _Vaclav Kotesovec_, Apr 10 2018
%p A187546 lahc := n -> if n=0 then 1 else binomial(2*n-1,n-1)*(2*n)!/n! fi;
%p A187546 seq(add(combinat[stirling1](n,k)*lahc(k), k=0..n), n=0..20);
%t A187546 lahc[n_] := If[n == 0, 1, Binomial[2n - 1, n - 1](2n)!/n!]
%t A187546 Table[Sum[StirlingS1[n, k]*lahc[k], {k, 0, n}], {n, 0, 20}]
%o A187546 (Maxima) lahc(n):= if n=0 then 1 else binomial(2*n-1,n-1)*(2*n)!/n!;
%o A187546 makelist(sum(stirling1(n,k)*lahc(k),k,0,n),n,0,12);
%Y A187546 Cf. A187536, A008297, A111596, A187536, A187538, A187539, A187540, A187542, A187543, A187544, A187545, A187547, A187548.
%K A187546 nonn,easy
%O A187546 0,2
%A A187546 _Emanuele Munarini_, Mar 11 2011