A153087 a(n) = A051717(3n) + A051717(3n+1) + A051717(3n+2).

6, 66, 114, 162, 5466, 1026, 1926, 606, 5466, 1746, 29154, 522, 3838386, 27066, 4302, 1254, 92886, 3246, 2466, 1578, 113573466, 1026, 129474, 9402, 280201746, 66, 236646, 231006, 6808626, 122826, 545646, 1422, 9003546, 66666, 10242, 2874, 418384938, 3344058

Offset: 0

Author

Paul Curtz, Dec 18 2008

Keywords

• nonn

Comments

All terms are multiples of 6.

The first differences are 60, 48, 48, 5304, -4440, ... Apparently (checked for the first 700 entries) these are multiples of 12.

Crossrefs

Cf. A051717, A140812.

Programs

Maple

C:=proc(n) if n=0 then RETURN(1); fi; if n mod 2 = 0 then RETURN(bernoulli(n)+bernoulli(n-1)); else RETURN(-bernoulli(n)-bernoulli(n-1)); fi; end:
A051717 := proc(n) denom(C(n)) ; end: A153087 := proc(n) A051717(3*n)+A051717(3*n+1)+A051717(3*n+2) ; end: seq(A153087(n),n=0..120) ; # R. J. Mathar, Sep 07 2009

Extensions

Extended by R. J. Mathar, Sep 07 2009