A175672 y-values in the solution to x^2 - 28*y^2=1.

0, 24, 6096, 1548360, 393277344, 99890897016, 25371894564720, 6444361328541864, 1636842405555068736, 415751526649658917080, 105599250926607809869584, 26821793983831734047957256

Offset

1,2

Comments

The corresponding values of x of this Pell equation are in A175633.

Links

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

Index entries for linear recurrences with constant coefficients, signature (254,-1).

Formula

a(n) = 254*a(n-1)-a(n-2) with a(1)=0, a(2)=24.

G.f.: 24*x^2/(1-254*x+x^2).

Mathematica

LinearRecurrence[{254, -1}, {0, 24}, 20]

Prog

(Magma) I:=[0, 24]; [n le 2 select I[n] else 254*Self(n-1)-Self(n-2): n in [1..15]];

Crossrefs

Cf. A175633.

Sequence in context: A277001 A163576 A145408 * A181749 A266312 A181232

Adjacent sequences: A175669 A175670 A175671 * A175673 A175674 A175675

Keyword

nonn,easy,less

Author

Vincenzo Librandi, Dec 04 2010

Status

approved