A154931 Third column of A154921.

1, 3, 18, 130, 1125, 11361, 131124, 1702548, 24562575, 389799355, 6748339158, 126565340694, 2556332651145, 55320126580005, 1276961156453160, 31318513972988008, 813295166343147315, 22293401161982239071, 643251586018800611370, 19488333337058966337930

Offset: 2

Author

Mats Granvik, Jan 17 2009

Keywords

• nonn
• easy

Links

• Alois P. Heinz, Table of n, a(n) for n = 2..424

Crossrefs

Cf. A154921.

Programs

Maple

b:= proc(n, p) option remember; `if`(n=0, p!,
      add(b(n-j, p+j)/j!, j=1..n))
    end:
a:= n-> b(n-2, 2)/2:
seq(a(n), n=2..23);  # Alois P. Heinz, Feb 03 2019

Mathematica

With[{nn=20},Drop[CoefficientList[Series[(x^2/2)/(2-Exp[x]),{x,0,nn}],x] Range[0,nn]!,2]] (* Harvey P. Dale, Jan 16 2013 *)

Formula

E.g.f.: 1/2!*x^2/(2-exp(x)) = x^2/2! + 3*x^3/3! + 18*x^4/4! + .... - Peter Bala, Apr 20 2012

Extensions

a(9) through a(18) from Peter Bala, Apr 20 2012

a(19)-a(21) from Alois P. Heinz, Feb 03 2019