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A174745
y-values in the solution to x^2 - 21*y^2 = 1.
3
0, 12, 1320, 145188, 15969360, 1756484412, 193197315960, 21249948271188, 2337301112514720, 257081872428348012, 28276668666005766600, 3110176471388205977988, 342091135184036651812080
OFFSET
1,2
COMMENTS
The corresponding values of x of this Pell equation are in A114049.
FORMULA
a(n) = 110*a(n-1)-a(n-2) with a(1)=0, a(2)=12.
G.f.: 12*x^2/(1-110*x+x^2).
MATHEMATICA
LinearRecurrence[{110, -1}, {0, 12}, 30]
PROG
(Magma) I:=[0, 12]; [n le 2 select I[n] else 110*Self(n-1)-Self(n-2): n in [1..20]];
CROSSREFS
Cf. A114049.
Sequence in context: A137343 A133461 A246981 * A071309 A067108 A240627
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Apr 14 2010
STATUS
approved