OFFSET
0,1
COMMENTS
Prime factors of a(n) are in the Cunningham Project.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
S. S. Wagstaff, Jr., The Cunningham Project.
Index entries for linear recurrences with constant coefficients, signature (13,-12).
FORMULA
O.g.f.: (2-13*x)/(1-13*x+12*x^2) = (2-13*x)/((1-x)(1-12*x)).
E.g.f.: exp(x) + exp(12*x). - Stefano Spezia, Mar 20 2023
From Elmo R. Oliveira, Dec 15 2023: (Start)
a(n) = 12*a(n-1) - 11 for n>0.
a(n) = 13*a(n-1) - 12*a(n-2) for n>1.
a(n) = (11*A016125(n) + 13)/12. (End)
EXAMPLE
a(3) = 12^3 + 1 = 1729.
MATHEMATICA
nmax = 17; 12^Range[0, nmax] + 1
LinearRecurrence[{13, -12}, {2, 13}, 20] (* Harvey P. Dale, Nov 02 2015 *)
PROG
(Magma) [12^n + 1: n in [0..20]]; // Vincenzo Librandi, May 02 2011
(PARI) vector(21, n, 12^(n-1)+1) \\ Charles R Greathouse IV, May 02 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Stuart Clary, Dec 20 2010
STATUS
approved