A289796 a(n) = (1/3)*A289795(n).

1, 8, 54, 361, 2420, 16227, 108802, 729512, 4891347, 32796280, 219897701, 1474404984, 9885824398, 66284043461, 444431768220, 2979896612959, 19980083465882, 133965632756376, 898234023419479, 6022621953315440, 40381430948778393, 270755823312682408

Offset: 0

Author

Clark Kimberling, Aug 12 2017

Keywords

• nonn
• easy

Comments

See A289780 for a guide to related sequences.

Links

• Clark Kimberling, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (7, -3, 7, -1)

Crossrefs

Cf. A289795, A289780.

Programs

Mathematica

z = 60; s = 3*x/(1 - x)^2; p = 1 - s - s^2;
Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A008585 *)
u = Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A289795 *)
u/3  (* A289796 *)

Formula

G.f.: (1 + x + x^2)/(1 - 7 x + 3 x^2 - 7 x^3 + x^4).

a(n) = 7*a(n-1) - 3*a(n-2) + 7*a(n-3) - a(n-4).