A141055 The n-th differences of the row A141045(n,.).

-1, -2, -60, -120, -5040, -10080, -302400, -604800, -39916800, -79833600, -217945728000, -435891456000, -2615348736000, -5230697472000, -2667655710720000, -5335311421440000, -4257578514309120000, -8515157028618240000, -2810001819444019200000

Offset: 0

Author

Paul Curtz, Aug 01 2008

Keywords

• sign

Comments

Can be thought of as the second sequence of a family: the first is A091137, the third starts 1, 2, 84, 168.

Examples

			The first differences of A141045(2,.) are 11-(-19)=30 and -19-11 = -30. The 2nd difference is a(2)= -30-30= -60.
		

Programs

Mathematica

a[n_] := a[n] = a[n-1]*If[OddQ[n], 2, Denominator[BernoulliB[n+2]]]; a[0]=-1; Table[a[n], {n, 0, 18}] (* Jean-François Alcover, Dec 17 2014 *)

PARI

a(n)=if(n,my(pr=a(n-1));fordiv(n+2,d,if(isprime(d+1),pr*=d+1));pr,-1) \\ Charles R Greathouse IV, Jul 08 2011

Formula

a(n+1) = a(n)*A027760(n+3).

Extensions

Edited and extended by R. J. Mathar, Aug 12 2008