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A153171
First differences of A046163.
1
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
0,1
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
MATHEMATICA
Differences[Table[Denominator[(n-1)^2/(n^2+n+1)], {n, 1, 50}]] (* Vaclav Kotesovec, Nov 04 2014 *)
PROG
(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
CROSSREFS
Cf. A046163.
Sequence in context: A360561 A109047 A337814 * A069525 A345991 A054435
KEYWORD
sign,easy
AUTHOR
Paul Curtz, Dec 20 2008
EXTENSIONS
Edited by N. J. A. Sloane, Dec 20 2008
More terms from Colin Barker, Nov 04 2014
STATUS
approved