A174765 y-values in the solution to x^2 - 19*y^2 = 1.

0, 39, 13260, 4508361, 1532829480, 521157514839, 177192022215780, 60244766395850361, 20483043382566906960, 6964174505306352516039, 2367798848760777288546300, 805044644404158971753225961

Offset: 1

Author

Vincenzo Librandi, Apr 14 2010

Keywords

• nonn
• easy

Comments

The corresponding values of x of this Pell equation are in A114048.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..200
• Index entries for linear recurrences with constant coefficients, signature (340,-1).

Crossrefs

Cf. A114048.

Programs

Magma

I:=[0, 39]; [n le 2 select I[n] else 340*Self(n-1)-Self(n-2): n in [1..20]];

Mathematica

LinearRecurrence[{340,-1},{0,39},30]

Formula

a(n) = 340*a(n-1)-a(n-2) with a(1)=0, a(2)=39.

G.f.: 39*x^2/(1-340*x+x^2).