OFFSET
0,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (11,-31,21).
FORMULA
G.f.: 1/(1-7*x)-1/(1-3*x)+1/(1-x).
E.g.f.: e^(7*x)-e^(3*x)+e^x.
a(n) = 10*a(n-1)-21*a(n-2)+12 with a(0)=1, a(1)=5. - Vincenzo Librandi, Jul 21 2010
PROG
(PARI) a(n)=7^n-3^n+1 \\ Charles R Greathouse IV, Oct 07 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Jan 26 2009
STATUS
approved