A153171 First differences of A046163.

6, 6, -6, 24, 12, -24, 54, 18, -54, 96, 24, -96, 150, 30, -150, 216, 36, -216, 294, 42, -294, 384, 48, -384, 486, 54, -486, 600, 60, -600, 726, 66, -726, 864, 72, -864, 1014, 78, -1014, 1176, 84, -1176, 1350, 90, -1350, 1536, 96, -1536, 1734, 102, -1734

Offset: 0

Author

Paul Curtz, Dec 20 2008

Keywords

• sign
• easy

Links

• Colin Barker, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (-1,-1,2,2,2,-1,-1,-1).

Crossrefs

Cf. A046163.

Programs

Mathematica

Differences[Table[Denominator[(n-1)^2/(n^2+n+1)],{n,1,50}]] (* Vaclav Kotesovec, Nov 04 2014 *)

PARI

Vec(6*(x^4+2*x^3+x^2+2*x+1)/((x-1)^2*(x^2+x+1)^3) + O(x^100)) \\ Colin Barker, Nov 04 2014

Formula

G.f.: 6*(x^4+2*x^3+x^2+2*x+1) / ((x-1)^2*(x^2+x+1)^3). - Colin Barker, Nov 04 2014

Extensions

Edited by N. J. A. Sloane, Dec 20 2008

More terms from Colin Barker, Nov 04 2014