OFFSET
0,1
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.: (12 + 47*x + 12*x^2)/((1 + x)*(1 - x)^2). - Vincenzo Librandi, Jun 06 2014
Sum_{n>=0} (-1)^n/a(n) = cot(12*Pi/71)*Pi/71. - Amiram Eldar, Feb 24 2023
MATHEMATICA
CoefficientList[Series[(12 + 47 x + 12 x^2)/((1 + x) (1 - x)^2), {x, 0, 50}], x] (* Vincenzo Librandi, Jun 06 2014 *)
LinearRecurrence[{1, 1, -1}, {12, 59, 83}, 50] (* Harvey P. Dale, Dec 09 2015 *)
PROG
(Magma) [(71/4)-(23/4)*(-1)^n+(71/2)*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