A081708 a(n) = a(n-1) + 64*a(n-2) starting with a(0) = 2 and a(1) = 1.

2, 1, 129, 193, 8449, 20801, 561537, 1892801, 37831169, 158970433, 2580165249, 12754272961, 177884848897, 994158318401, 12378788647809, 76004921025473, 868247394485249, 5732562340115521, 61300395587171457, 428184385354564801, 4351409702933538049

Offset: 0

Author

Helmut Schmiedel (a.positiv(AT)web.de), Apr 03 2003

Keywords

• nonn
• easy

Links

• Colin Barker, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (1,64).

Crossrefs

Cf. A072265.

Programs

PARI

a(n) = my(w = quadgen(257)); w^n + (1 - w)^n;

PARI

Vec((2-x)/(1-x-64*x^2) + O(x^30)) \\ Colin Barker, Feb 22 2016

Formula

a(n) = ((1 + sqrt(257))/2)^n + ((1 - sqrt(257))/2)^n.

G.f.: (2-x) / (1-x-64*x^2). - Colin Barker, Feb 22 2016

Extensions

More terms from Michel Marcus, Aug 24 2013