A153122 G.f.: 1/p(x) where p(x)=x^5 + 2x^4 - 2x^3 - x^2 + 2x - 1.

1, -2, 6, -15, 38, -95, 237, -590, 1468, -3651, 9079, -22575, 56131, -139563, 347004, -862774, 2145156, -5333599, 13261165, -32971820, 81979285, -203828691, 506788203, -1260049698, 3132916721, -7789507968, 19367394583, -48154000782

Offset: 0

Author

Roger L. Bagula and Gary W. Adamson, Dec 18 2008

Keywords

• sign
• easy

Comments

a(n)/a(n-1) tends to the approximation to Feigenbaum's constant mentioned in A103546. = 2.48634376497....;.

Links

• Weisstein, Eric W. Feigenbaum Constant. Equation (11).
• Index entries for linear recurrences with constant coefficients, signature (-2,2,1,-2,1).

Crossrefs

Cf. A103546.

Programs

Mathematica

f[x_] = x^5 + 2x^4 - 2x^3 - x^2 + 2x - 1;
g[x] = ExpandAll[x^5*f[1/x]]'
a = Table[SeriesCoefficient[Series[1/g[x], {x, 0, 50}], n], {n, 0, 50}]

Formula

p(x)=x^5 + 2x^4 - 2x^3 - x^2 + 2x - 1; a(n)=coefficient_expansion(1/(x^5*p(1/x))).

Extensions

Edited by N. J. A. Sloane, Dec 19 2008