A174756 x-values in the solution to x^2-51*y^2=1.

1, 50, 4999, 499850, 49980001, 4997500250, 499700044999, 49965006999650, 4996000999920001, 499550134985000450, 49950017497500124999, 4994502199615027499450, 499400269944005249820001

Offset

1,2

Comments

The corresponding values of y of this Pell equation are in A174855.

Links

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

Index entries for linear recurrences with constant coefficients, signature (100,-1).

Formula

a(n) = 100*a(n-1)-a(n-2) with a(1)=1, a(2)=50.

G.f.: x*(1-50*x)/(1-100*x+x^2).

Mathematica

LinearRecurrence[{100, -1}, {1, 50}, 30]

Prog

(Magma) I:=[1, 50]; [n le 2 select I[n] else 100*Self(n-1)-Self(n-2): n in [1..20]];

Crossrefs

Cf. A174855.

Sequence in context: A010564 A183689 A248205 * A231937 A230477 A320099

Adjacent sequences: A174753 A174754 A174755 * A174757 A174758 A174759

Keyword

nonn,easy

Author

Vincenzo Librandi, Apr 13 2010

Status

approved