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A199031
a(n) = 2*12^n-1.
1
1, 23, 287, 3455, 41471, 497663, 5971967, 71663615, 859963391, 10319560703, 123834728447, 1486016741375, 17832200896511, 213986410758143, 2567836929097727, 30814043149172735, 369768517790072831, 4437222213480873983
OFFSET
0,2
FORMULA
a(n) = 12*a(n-1)+11.
a(n) = 13*a(n-1)-12*a(n-2).
G.f.: (1+10*x)/((1-x)*(1-12*x)). - Bruno Berselli, Nov 03 2011
MATHEMATICA
LinearRecurrence[{13, -12}, {1, 23}, 40] (* Harvey P. Dale, Feb 21 2013 *)
PROG
(Magma) [2*12^n-1: n in [0..20]];
CROSSREFS
Sequence in context: A010975 A022588 A268992 * A125435 A086943 A131273
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Nov 03 2011
STATUS
approved