A291986 Expansion of 1/((1-x)*(1-2*x^2)*(1-3*x^3)).

1, 1, 3, 6, 10, 16, 33, 45, 79, 130, 198, 300, 517, 721, 1155, 1806, 2674, 3976, 6441, 9045, 13975, 21370, 31230, 46020, 72301, 101881, 154443, 233286, 338410, 496096, 765393, 1080765, 1619359, 2427250, 3504438, 5120220, 7806037, 11037601, 16409235, 24466686

Offset: 0

Author

Seiichi Manyama, Sep 07 2017

Keywords

• nonn
• easy

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..6278
• Index entries for linear recurrences with constant coefficients, signature (1, 2, 1, -3, -6, 6).

Crossrefs

Cf. A291960, A291987, A291988.

Programs

Mathematica

CoefficientList[Series[1/((1-x)(1-2x^2)(1-3x^3)),{x,0,40}],x] (* or *) LinearRecurrence[{1,2,1,-3,-6,6},{1,1,3,6,10,16},40] (* Harvey P. Dale, Sep 15 2023 *)

PARI

Vec(1/((1-x)*(1-2*x^2)*(1-3*x^3)) + O(x^100))