A280757 Expansion of x*(2 + x)/(1 - 4*x^2 - x^3 + x^4).

0, 2, 1, 8, 6, 31, 31, 122, 149, 488, 687, 1979, 3087, 8115, 13640, 33568, 59588, 139797, 258280, 585208, 1113329, 2459315, 4780244, 10365381, 20466962, 43782453, 87452985, 185231393, 373127431, 784596104, 1590288132, 3326280454, 6772621201, 14110813844, 28826477126, 59889596123

Offset

0,2

Links

Harvey P. Dale, Table of n, a(n) for n = 0..1000

R. Sachdeva and A. K. Agarwal, Combinatorics of certain restricted n-color composition functions, Discrete Mathematics, 340, (2017), 361-372. See sequence C_4.

Index entries for linear recurrences with constant coefficients, signature (0,4,1,-1).

Mathematica

CoefficientList[Series[x (2+x)/(1-4x^2-x^3+x^4), {x, 0, 40}], x] (* or *) LinearRecurrence[{0, 4, 1, -1}, {0, 2, 1, 8}, 40] (* Harvey P. Dale, May 14 2024 *)

Crossrefs

Sequence in context: A324124 A019816 A214562 * A298641 A293415 A197018

Adjacent sequences: A280754 A280755 A280756 * A280758 A280759 A280760

Keyword

nonn,easy,changed

Author

N. J. A. Sloane, Jan 16 2017

Status

approved