The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A176377 x-values in the solution to x^2-70*y^2=1. 2
 1, 251, 126001, 63252251, 31752504001, 15939693756251, 8001694513134001, 4016834705899512251, 2016443020667042016001, 1012250379540149192520251, 508147674086134227603150001, 255089120140859842107588780251 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The corresponding values of y of this Pell equation are in A176378. LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..200 Index entries for linear recurrences with constant coefficients, signature (502,-1). FORMULA a(n) = 502*a(n-1)-a(n-2) with a(1)=1, a(2)=251. G.f.: x*(1-251*x)/(1-502*x+x^2). - Harvey P. Dale, Jun 14 2011 MATHEMATICA LinearRecurrence[{502, -1}, {1, 251}, 20] (* or *) CoefficientList[ Series[ (1-251 x)/(1-502 x+x^2), {x, 0, 20}], x] (* Harvey P. Dale, Jun 14 2011 *) PROG (PARI) Vec((1-251*x)/(1-502*x+x^2)+O(x^99)) \\ Charles R Greathouse IV, Jun 14 2011 (MAGMA) I:=[1, 251]; [n le 2 select I[n] else 502*Self(n-1)-Self(n-2): n in [1..20]]; CROSSREFS Sequence in context: A078968 A052239 A089236 * A268848 A177809 A113899 Adjacent sequences:  A176374 A176375 A176376 * A176378 A176379 A176380 KEYWORD nonn,easy AUTHOR Vincenzo Librandi, Apr 16 2010 EXTENSIONS Definition rewritten and g.f. adapted to the offset from Bruno Berselli, Dec 15 2011 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 5 09:32 EDT 2020. Contains 334829 sequences. (Running on oeis4.)