OFFSET
1,1
LINKS
FORMULA
G.f.: x*(2+3*x^2) / ( (x-1)*(4*x-1)*(1+x+x^2) ). - R. J. Mathar, Apr 27 2015
PROG
(PARI) a(n)=([0, 1, 0, 0; 0, 0, 1, 0; 0, 0, 0, 1; -4, 1, 0, 4]^(n-1)*[2; 8; 35; 142])[1, 1] \\ Charles R Greathouse IV, Feb 13 2017
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
STATUS
approved