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A280757
Expansion of x*(2 + x)/(1 - 4*x^2 - x^3 + x^4).
1
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
R. Sachdeva and A. K. Agarwal, Combinatorics of certain restricted n-color composition functions, Discrete Mathematics, 340, (2017), 361-372. See sequence C_4.
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
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jan 16 2017
STATUS
approved