A145305 Numbers Y such that 237*Y^2+79 is a square.

195, 88979085, 40601334443475, 18526470109137550365, 8453665363699081172206755, 3857424412768091666931149169645, 1760150474386452098440318147235146035, 803160181759629441009745959552760456892925, 366483597255522282717242648737403383853920317315

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..180

Index entries for linear recurrences with constant coefficients, signature (456302,-1).

Formula

a(n+2) = 456302*a(n+1)-a(n).

G.f.: 195*x*(x+1) / (x^2-456302*x+1). - Colin Barker, Oct 20 2014

Example

a(1)=195 because the first relation is : 3002^2=237*195^2+79.

Mathematica

CoefficientList[Series[195 (x + 1)/(x^2 - 456302 x + 1), {x, 0, 20}], x] (* Vincenzo Librandi, Oct 21 2014 *)
LinearRecurrence[{456302, -1}, {195, 88979085}, 20] (* Harvey P. Dale, Jan 19 2020 *)

Prog

(PARI) Vec(195*x*(x+1)/(x^2-456302*x+1) + O(x^20)) \\ Colin Barker, Oct 20 2014
(Magma) I:=[195, 88979085]; [n le 2 select I[n] else 456302*Self(n-1)-Self(n-2): n in [1..10]]; // Vincenzo Librandi, Oct 21 2014

Crossrefs

Sequence in context: A226105 A164130 A084232 * A174890 A077594 A306359

Adjacent sequences: A145302 A145303 A145304 * A145306 A145307 A145308

Keyword

easy,nonn

Author

Richard Choulet, Oct 06 2008

Extensions

Editing and more terms from Colin Barker, Oct 20 2014

Status

approved