The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A105175 Numbers such that 71*(a(n)^2) + 71*a(n) + 1 is a square. 0
 0, 0, 9235919, 14984879, 447402699579360, 725891508817440, 21672901717138141202159, 35163344661747893105039, 1049869992475115099179547651520, 1703368606439836689249786415680, 50857380127742528965284060018658947599, 82513897278978744922944413386362572399 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Table of n, a(n) for n=1..12. Index entries for linear recurrences with constant coefficients, signature (1,48441598,-48441598,-1,1). FORMULA Define a(1)=0, a(2)=0, a(3)=9235919, a(4)=14984879. Then a(n) = (a(3)+a(4)+1) * (2*a(n-2)+1) - a(n-3) - 1. G.f.: -413*x^3*(22363*x^2+13920*x+22363) / ((x-1)*(x^2-6960*x+1)*(x^2+6960*x+1)). - Colin Barker, Apr 17 2014 MATHEMATICA CoefficientList[Series[-413*x^2*(22363*x^2 + 13920*x + 22363)/((x - 1)*(x^2 - 6960*x + 1)*(x^2 + 6960*x + 1)), {x, 0, 12}], x] (* Wesley Ivan Hurt, Apr 23 2017 *) LinearRecurrence[{1, 48441598, -48441598, -1, 1}, {0, 0, 9235919, 14984879, 447402699579360}, 20] (* Harvey P. Dale, Nov 20 2022 *) PROG (PARI) concat([0, 0], Vec(-413*x^3*(22363*x^2+13920*x+22363) / ((x-1)*(x^2-6960*x+1)*(x^2+6960*x+1)) + O(x^100))) \\ Colin Barker, Apr 17 2014 CROSSREFS Sequence in context: A206599 A245746 A206098 * A212469 A251280 A234395 Adjacent sequences: A105172 A105173 A105174 * A105176 A105177 A105178 KEYWORD nonn,easy AUTHOR Pierre CAMI, Apr 11 2005 EXTENSIONS More terms from Colin Barker, Apr 17 2014 STATUS approved

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

Last modified June 17 23:38 EDT 2024. Contains 373468 sequences. (Running on oeis4.)