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A155603
a(n) = 5^n+3^n-1.
13
1, 7, 33, 151, 705, 3367, 16353, 80311, 397185, 1972807, 9824673, 49005271, 244672065, 1222297447, 6108298593, 30531927031, 152630937345, 763068593287, 3815084686113, 19074648589591, 95370918425025, 476847618556327
OFFSET
0,2
FORMULA
G.f.: 1/(1-5*x)+1/(1-3*x)-1/(1-x).
E.g.f.: e^(5*x)+e^(3*x)-e^x.
a(n) = 8*a(n-1)-15*a(n-2)-8 with a(0)=1, a(1)=7. - Vincenzo Librandi, Jul 21 2010
a(n) = A074606(n)-1. - R. J. Mathar, Mar 10 2022
MATHEMATICA
Table[5^n+3^n-1, {n, 0, 30}] (* or *) LinearRecurrence[{9, -23, 15}, {1, 7, 33}, 30] (* Harvey P. Dale, Oct 14 2020 *)
PROG
(PARI) a(n)=5^n+3^n-1 \\ Charles R Greathouse IV, Jun 11 2015
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Jan 25 2009
STATUS
approved