A279779 Coefficients in the expansion of 1/([r] + [2r]x + [3r]x^2 + ...); [ ] = floor, r = 7/5.

1, -2, 0, 3, -3, 0, 4, -7, 5, 5, -16, 15, 2, -26, 39, -19, -37, 88, -73, -28, 160, -207, 61, 249, -484, 339, 258, -950, 1063, -99, -1593, 2628, -1469, -1996, 5492, -5287, -763, 9837, -14008, 5671, 14034, -31042, 25319, 11389, -59053, 73040, -16961, -92844

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,-2,-1,-2).

Crossrefs

Cf. A279634, A279778, A279780, A279781.

Programs

Mathematica

z = 50; f[x_] := f[x] = Sum[Floor[(7/5)*(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 = 7/5.

G.f.: (1 - x) (1 - x^5)/(1 + x + 2 x^2 + x^3 + 2 x^4).