OFFSET
0,2
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (4,2).
FORMULA
a(n) = A335312(n, 6).
From Colin Barker, Jun 24 2020: (Start)
G.f.: (1 + 4*x) / (1 - 4*x - 2*x^2) for n>1.
a(n) = 4*a(n-1) + 2*a(n-2). (End)
MAPLE
aList := proc(len) local H; H := (x, y) -> exp(2*x)*(y*sinh(x*y) + cosh(x*y)):
series(H(x, sqrt(6)), x, len + 1): seq(k!*coeff(%, x, k), k=0..len-1) end:
aList(25);
MATHEMATICA
LinearRecurrence[{4, 2}, {1, 8}, 30] (* Paolo Xausa, Feb 01 2024 *)
PROG
(PARI) Vec((1 + 4*x) / (1 - 4*x - 2*x^2) + O(x^25)) \\ Colin Barker, Jun 25 2020
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Peter Luschny, Jun 24 2020
STATUS
approved