A293989 a(0) = a(1) = 1 and a(n) = n! * [x^n] exp((1/(1-x)^(n-1) - 1)/(n-1)) for n > 1.

1, 1, 3, 22, 273, 4956, 122215, 3909228, 156878337, 7694191648, 451507161771, 31157580173160, 2493155105671153, 228656777880920832, 23802477358410219183, 2788676280294791340496, 364998736798930722881025, 53020798447231578364796928

Offset: 0

Author

Seiichi Manyama, Oct 21 2017

Keywords

• nonn

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..281

Crossrefs

Main diagonal of A291709.

Programs

Mathematica

a[0]= a[1]= 1; a[n_]:= n! * SeriesCoefficient[Exp[(1/(1-x)^(n-1) - 1)/(n-1)] ,{x,0,n}]; Array[a,18,0] (* Stefano Spezia, Mar 24 2025 *)