A014903 a(1)=1, a(n) = 19*a(n-1) + n.

1, 21, 402, 7642, 145203, 2758863, 52418404, 995949684, 18923044005, 359537836105, 6831218886006, 129793158834126, 2466070017848407, 46855330339119747, 890251276443275208, 16914774252422228968, 321380710796022350409, 6106233505124424657789

Offset

1,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..200

Index entries for linear recurrences with constant coefficients, signature (21, -39, 19).

Formula

a(1)=1, a(2)=21, a(3)=402, a(n) = 21*a(n-1) - 39*a(n-2) + 19*a(n-3). - Vincenzo Librandi, Oct 20 2012

Mathematica

LinearRecurrence[{21, -39, 19}, {1, 21, 402}, 20] (* Vincenzo Librandi, Oct 20 2012 *)

Prog

(Magma) I:=[1, 21, 402]; [n le 3 select I[n] else 21*Self(n-1) - 39*Self(n-2) + 19*Self(n-3): n in [1..20]]; // Vincenzo Librandi, Oct 20 2012

Crossrefs

Sequence in context: A113363 A223459 A240655 * A219308 A358698 A020534

Adjacent sequences: A014900 A014901 A014902 * A014904 A014905 A014906

Keyword

nonn

Author

N. J. A. Sloane, Olivier Gérard

Status

approved