OFFSET
1,2
LINKS
FORMULA
a(n) = 5a(n-1) + a(n-2) - 5a(n-3).
a(n) = (-1)^n/12 -3/8 +7*5^n/24. G.f. x*(1+2*x) / ( (x-1)*(5*x-1)*(1+x) ). - R. J. Mathar, Nov 02 2011
PROG
(PARI) a(n)=([0, 1, 0; 0, 0, 1; -5, 1, 5]^(n-1)*[1; 7; 36])[1, 1] \\ Charles R Greathouse IV, Feb 13 2017
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
STATUS
approved