OFFSET
0,2
LINKS
FORMULA
G.f: (1+x-x^2+4*x^3-7*x^4)/(1-x)+(14*x^4)/(1-2*x).
EXAMPLE
a(4) = 14-2 = 12.
a(5) = 7*4-2 = 26.
MAPLE
taylor(1+2*z+z^2+5*z^3-((2*z^4)/(1-z))+((14*z^4)/(1-2*z)), z=0, 50);
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Richard Choulet, Mar 15 2010
EXTENSIONS
Definition edited by Olivier Gérard, Oct 24 2012
STATUS
approved