OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..300
Index entries for linear recurrences with constant coefficients, signature (5,5,-25).
FORMULA
a(n) = 5*a(n-1) + 5*a(n-2) - 25*a(n-3); a(0)=1, a(1)=3, a(2)=15. - Harvey P. Dale, May 05 2011
G.f.: (1 - 2x - 5x^2)/(1 - 5x - 5x^2 + 25x^3). - Harvey P. Dale, May 05 2011
MATHEMATICA
Table[(5^n+5^Floor[n/2])/2, {n, 0, 20}] (* or *) LinearRecurrence[ {5, 5, -25}, {1, 3, 15}, 50](* Harvey P. Dale, May 05 2011 *)
PROG
(PARI) a(n)=(5^n+5^(n\2))/2 \\ Charles R Greathouse IV, Apr 17 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved