A279678 Coefficients in the expansion of 1/([r] + [2r]x + [3r]x^2 + ...); [ ] = floor, r = 7/4.

1, -3, 4, -4, 5, -9, 16, -24, 34, -52, 84, -132, 200, -304, 472, -736, 1136, -1744, 2688, -4160, 6432, -9920, 15296, -23616, 36480, -56320, 86912, -134144, 207104, -319744, 493568, -761856, 1176064, -1815552, 2802688, -4326400, 6678528, -10309632, 15915008

Offset: 0

Author

Clark Kimberling, Dec 18 2016

Keywords

• sign
• easy

Comments

If n >=18, then 32 divides a(n).

Links

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

Crossrefs

Cf. A279634, A279677.

Programs

Mathematica

z = 50; f[x_] := f[x] = Sum[Floor[(7/4)*(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 = 7/4.

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