A087152 Expansion of (1-sqrt(1-4*log(1+x)))/log(1+x)/2.

1, 3, 20, 194, 2554, 42226, 843744, 19769256, 531768120, 16152296424, 546895099200, 20425461026736, 834215500905552, 36988602430554576, 1769524998544143360, 90851799797294235264, 4982968503277896871296

Offset: 1

Author

Vladeta Jovovic, Oct 18 2003

Keywords

• nonn

Links

• G. C. Greubel, Table of n, a(n) for n = 1..370

Crossrefs

Cf. A000108, A052851, A052803, A052886, A052895, A006531, A048287.

Programs

Mathematica

Rest[CoefficientList[Series[(1-Sqrt[1-4*Log[1+x]])/Log[1+x]/2, {x, 0, 20}], x] * Range[0, 20]!] (* Vaclav Kotesovec, May 03 2015 *)

PARI

x='x+O('x^50); Vec(serlaplace((1-sqrt(1-4*log(1+x)))/log(1+x)/2 - 1)) \\ G. C. Greubel, May 24 2017

Formula

a(n) = Sum_{k=0..n} Stirling1(n, k)*k!*Catalan(k).

a(n) ~ 2*n! / (exp(1/8)*sqrt(Pi) * (exp(1/4)-1)^(n-1/2) * n^(3/2)). - Vaclav Kotesovec, May 03 2015