OFFSET
0,1
COMMENTS
Numbers k such that k^2 == 2 (mod 79). - Vincenzo Librandi, Jun 25 2014
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (1,1,-1).
FORMULA
G.f.: (9 + 61*x + 9*x^2)/((1 + x)*(1 - x)^2). - Vincenzo Librandi, Jun 06 2014
Sum_{n>=0} (-1)^n/a(n) = cot(9*Pi/79)*Pi/79. - Amiram Eldar, Feb 24 2023
MATHEMATICA
CoefficientList[Series[(9 + 61 x + 9 x^2)/((1 + x) (1 - x)^2), {x, 0, 50}], x] (* Vincenzo Librandi, Jun 06 2014 *)
PROG
(Magma) [(79/4)-(43/4)*(-1)^n+(79/2)*n: n in [0..50]]; // Vincenzo Librandi, Jun 06 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Nov 06 2009
EXTENSIONS
Edited by N. J. A. Sloane, Jun 23 2010
STATUS
approved