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A155613
8^n - 3^n + 1.
7
1, 6, 56, 486, 4016, 32526, 261416, 2094966, 16770656, 134198046, 1073682776, 8589757446, 68718945296, 549754219566, 4398041728136, 35184357739926, 281474933663936, 2251799684545086, 18014398122061496, 144115186913594406
OFFSET
0,2
FORMULA
G.f.: 1/(1-8*x)-1/(1-3*x)+1/(1-x).
E.g.f.: e^(8*x)-e^(3*x)+e^x.
a(n) = 11*a(n-1)-24*a(n-2)+14 with a(0)=1, a(1)=6. - Vincenzo Librandi, Jul 21 2010
MATHEMATICA
Table[8^n-3^n+1, {n, 0, 20}] (* or *) LinearRecurrence[{12, -35, 24}, {1, 6, 56}, 20] (* Harvey P. Dale, Mar 12 2014 *)
PROG
(PARI) a(n)=8^n-3^n+1 \\ Charles R Greathouse IV, Oct 07 2015
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Jan 26 2009
STATUS
approved