A174752 x-values in the solution to x^2-41*y^2=1.

1, 2049, 8396801, 34410088449, 141012534067201, 577869330197301249, 2368108374136006451201, 9704507539340024239720449, 39769069528107045198367948801, 162973637221675131882887614466049

Offset

1,2

Comments

The corresponding values of y of this Pell equation are in A174778.

Links

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

Index entries for linear recurrences with constant coefficients, signature (4098,-1).

Formula

a(n) = 4098*a(n-1)-a(n-2) with a(1)=1, a(2)=2049.

G.f.: x*(1-2049*x)/(1-4098*x+x^2).

Mathematica

LinearRecurrence[{4098, -1}, {1, 2049}, 30]

Prog

(Magma) I:=[1, 2049]; [n le 2 select I[n] else 4098*Self(n-1)-Self(n-2): n in [1..20]];

Crossrefs

Cf. A174778.

Sequence in context: A013959 A036089 A123095 * A045059 A224119 A183842

Adjacent sequences: A174749 A174750 A174751 * A174753 A174754 A174755

Keyword

nonn,easy

Author

Vincenzo Librandi, Apr 13 2010

Status

approved