OFFSET
0,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (9,-20,12).
FORMULA
G.f.: 1/(1-6*x)-1/(1-2*x)+1/(1-x).
E.g.f.: exp(6*x)-exp(2*x)+exp(x).
a(n) = 8*a(n-1)-12*a(n-2)+5 with a(0)=1, a(1)=5. - Vincenzo Librandi, Jul 21 2010
a(0)=1, a(1)=5, a(2)=33, a(n) = 9*a(n-1)-20*a(n-2)+12*a(n-3). - Harvey P. Dale, Jul 13 2011
a(n) = A248216(n)+1. - R. J. Mathar, Mar 10 2022
MATHEMATICA
Table[6^n-2^n+1, {n, 0, 20}] (* or *) LinearRecurrence[{9, -20, 12}, {1, 5, 33}, 20] (* Harvey P. Dale, Jul 13 2011 *)
PROG
(PARI) a(n) = 6^n-2^n+1 \\ Charles R Greathouse IV, Jul 25 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Jan 25 2009
STATUS
approved