A279677 Coefficients in the expansion of 1/([r] + [2r]x + [3r]x^2 + ...); [ ] = floor, r = 5/4.

1, -2, 1, -1, 3, -3, 2, -5, 9, -8, 9, -19, 26, -25, 37, -64, 77, -87, 138, -205, 241, -312, 481, -651, 794, -1105, 1613, -2096, 2693, -3823, 5322, -6885, 9209, -12968, 17529, -22979, 31386, -43465, 58037, -77344, 106237, -144967, 193418, -260925, 357441

Offset: 0

Author

Clark Kimberling, Dec 18 2016

Keywords

• sign
• easy

Links

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

Crossrefs

Cf. A279634, A279678.

Programs

Mathematica

z = 50; f[x_] := f[x] = Sum[Floor[(5/4)*(k + 1)] x^k, {k, 0, z}]; f[x]
CoefficientList[Series[1/f[x], {x, 0, z}], x]

Formula

G.f.: 1/([r] + [2r]x + [3r]x^2 + ...); [ ] = floor, r = 5/4.

G.f.: (1 - x) (1 - x^4)/(1 + x + x^2 + 2 x^3).