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A147663
Expansion of 1/(1 - x - x^2 + x^3 - x^7 + x^9 - x^11).
23
1, 1, 2, 2, 3, 3, 4, 5, 7, 9, 12, 16, 21, 28, 37, 50, 66, 88, 116, 154, 203, 269, 356, 472, 625, 828, 1097, 1453, 1925, 2550, 3379, 4476, 5930, 7855, 10406, 13784, 18260, 24189, 32044, 42449, 56233, 74493, 98682, 130726, 173175, 229409, 303902, 402585
OFFSET
0,3
FORMULA
G.f.: -1/((x^3 + x^2 - 1)*(x^8 - x^7 + x^5 - x^4 + x^3 - x + 1)). - Colin Barker, Sep 18 2013
a(n) = a(n-1) + a(n-2) - a(n-3) + a(n-7) - a(n-9) + a(n-10), n >= 10. - Franck Maminirina Ramaharo, Oct 31 2018
MATHEMATICA
CoefficientList[Series[1/(1 - x - x^2 + x^3 - x^7 + x^9 - x^11), {x, 0, 50}], x] (* Franck Maminirina Ramaharo, Oct 31 2018 *)
LinearRecurrence[{1, 1, -1, 0, 0, 0, 1, 0, -1, 0, 1}, {1, 1, 2, 2, 3, 3, 4, 5, 7, 9, 12}, 50] (* Harvey P. Dale, May 31 2020 *)
PROG
(PARI) Vec(-1/((x^3+x^2-1)*(x^8-x^7+x^5-x^4+x^3-x+1)) + O(x^50)) \\ Colin Barker, Sep 18 2013
(Magma) m:=50; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/(1 -x-x^2+x^3-x^7+x^9-x^11))); // G. C. Greubel, Nov 03 2018
KEYWORD
nonn,easy
AUTHOR
Roger L. Bagula, Nov 09 2008
EXTENSIONS
Heavily edited (because the Name, Comments, Formula and Mathematica code did not correspond to the terms of the sequence) by Colin Barker, Sep 18 2013
STATUS
approved