A280756 Expansion of (1 + 2*x)/(1 - x - 4*x^2 + x^4).

1, 3, 7, 19, 46, 119, 296, 753, 1891, 4784, 12052, 30435, 76752, 193708, 488664, 1233061, 3110965, 7849501, 19804697, 49969640, 126077463, 318106522, 802611677, 2025068125, 5109437370, 12891603348, 32526741151, 82068086418, 207065613652, 522446355976, 1318182069433, 3325899406919

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_5.

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

Mathematica

CoefficientList[Series[(1+2x)/(1-x-4x^2+x^4), {x, 0, 40}], x] (* or *) LinearRecurrence[ {1, 4, 0, -1}, {1, 3, 7, 19}, 40] (* Harvey P. Dale, Jun 23 2022 *)

Crossrefs

Sequence in context: A348008 A185696 A141344 * A029855 A209397 A110014

Adjacent sequences: A280753 A280754 A280755 * A280757 A280758 A280759

Keyword

nonn,easy

Author

N. J. A. Sloane, Jan 16 2017

Status

approved