A176381 y-values in the solution to x^2-71*y^2=1.

0, 413, 2874480, 20006380387, 139244404619040, 969141036142138013, 6745221472304875951440, 46946740478100900479884387, 326749306982360795035119382080

Offset

1,2

Comments

The corresponding values of x of this Pell equation are in A176380.

Links

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

Index entries for linear recurrences with constant coefficients, signature (6960,-1).

Formula

a(n) = 6960*a(n-1)-a(n-2) with a(1)=0, a(2)=413.

G.f.: 413*x^2/(1-6960*x+x^2).

Mathematica

LinearRecurrence[{6960, -1}, {0, 413}, 20]

Prog

(Magma) I:=[0, 413]; [n le 2 select I[n] else 6960*Self(n-1)-Self(n-2): n in [1..20]];

Crossrefs

Cf. A176380.

Sequence in context: A331825 A250945 A205585 * A027661 A260472 A253489

Adjacent sequences: A176378 A176379 A176380 * A176382 A176383 A176384

Keyword

nonn,easy

Author

Vincenzo Librandi, Apr 16 2010

Status

approved