A174766 y-values in the solution to x^2 - 22*y^2 = 1.

0, 42, 16548, 6519870, 2568812232, 1012105499538, 398766998005740, 157113185108762022, 61902196165854230928, 24389308176161458223610, 9609325519211448685871412, 3786049865261134620775112718

Offset: 1

Author

Vincenzo Librandi, Apr 14 2010

Keywords

• nonn
• easy

Comments

The corresponding values of x of this Pell equation are in A114050.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..200
• Index entries for linear recurrences with constant coefficients, signature (394,-1).

Crossrefs

Cf. A114050.

Programs

Magma

I:=[0, 42]; [n le 2 select I[n] else 394*Self(n-1)-Self(n-2): n in [1..20]];

Mathematica

LinearRecurrence[{394,-1},{0,42},30]

Formula

a(n) = 394*a(n-1)-a(n-2) with a(1)=0, a(2)=42.

G.f.: 42*x^2/(1-394*x+x^2).