A279778 Coefficients in the expansion of 1/([r] + [2r]x + [3r]x^2 + ...); [ ] = floor, r = 6/5.

1, -2, 1, 0, -1, 3, -3, 1, 1, -5, 9, -7, 1, 7, -19, 25, -15, -5, 33, -63, 65, -25, -43, 129, -191, 155, -7, -215, 449, -537, 317, 201, -879, 1435, -1391, 433, 1281, -3193, 4261, -3215, -415, 5755, -10647, 11737, -6015, -6585, 22157, -33031, 29489, -5445

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,-1,-2).

Crossrefs

Cf. A279634, A279779, A279780, A279781.

Programs

Mathematica

z = 50; f[x_] := f[x] = Sum[Floor[(6/5)*(k + 1)] x^k, {k, 0, z}]; f[x]
CoefficientList[Series[1/f[x], {x, 0, z}], x]
LinearRecurrence[{-1,-1,-1,-2},{1,-2,0,-1,3,-3},50] (* Harvey P. Dale, Mar 11 2024 *)

Formula

G.f.: 1/([r] + [2r]x + [3r]x^2 + ...); [ ] = floor, r = 6/5.

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