A159289 a(n+1) = 5*a(n) - 2*a(n-1).

5, 21, 95, 433, 1975, 9009, 41095, 187457, 855095, 3900561, 17792615, 81161953, 370224535, 1688798769, 7703544775, 35140126337, 160293542135, 731187458001, 3335350205735, 15214376112673, 69401180151895, 316577148534129

Offset: 0

Author

Creighton Dement, Apr 08 2009

Keywords

• nonn
• easy

Links

• G. C. Greubel, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (5, -2).

Crossrefs

Cf. A107839.

Programs

Magma

I:=[5, 21]; [n le 2 select I[n] else 5*Self(n-1) - 2*Self(n-2): n in [1..30]]; // G. C. Greubel, Jun 27 2018

Mathematica

LinearRecurrence[{5, -2}, {5, 21}, 50] (* G. C. Greubel, Jun 27 2018 *)

PARI

x='x+O('x^30); Vec(-(-5+4*x)/(1-5*x+2*x^2)) \\ G. C. Greubel, Jun 27 2018

Formula

From R. J. Mathar, Apr 10 2009: (Start)

G.f.: -(-5+4*x)/(1-5*x+2*x^2).

a(n) = 5*A107839(n) - 4*A107839(n-1). (End)