A275907 Expansion of (1+x-x^3) / (1-4*x-x^4-x^5).

1, 5, 20, 79, 317, 1274, 5121, 20583, 82728, 332503, 1336407, 5371332, 21588639, 86769787, 348748058, 1401699971, 5633759855, 22643397846, 91009109229, 365786884945, 1470182999606, 5909009156125, 23749689131575, 95455552520474, 383658179966447, 1542011912021519, 6197706346373776

Offset

0,2

Links

Colin Barker, Table of n, a(n) for n = 0..1000

T. Doslic, T. Short, Maximal matchings in polyspiro and benzenoid chains, arXiv:1511.00590, [math.CO], 2015. See Th. 4.4.

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

Formula

G.f.: (1+x-x^3) / (1-4*x-x^4-x^5).

a(n) = 4*a(n-1)+a(n-4)+a(n-5) for n>4. - Colin Barker, Aug 26 2016

Mathematica

CoefficientList[Series[(1 + x - x^3)/(1 - 4*x - x^4 - x^5), {x, 0, 30}], x] (* Wesley Ivan Hurt, Sep 05 2022 *)

Prog

(PARI) Vec((1+x-x^3)/(1-4*x-x^4-x^5) + O(x^30)) \\ Colin Barker, Aug 26 2016

Crossrefs

Sequence in context: A028814 A346394 A079820 * A117422 A154639 A214939

Adjacent sequences: A275904 A275905 A275906 * A275908 A275909 A275910

Keyword

nonn,easy

Author

N. J. A. Sloane, Aug 25 2016

Status

approved