OFFSET
5,1
LINKS
Index entries for linear recurrences with constant coefficients, signature (3,-3,1,0,1,-3,3,-1).
FORMULA
a(n)=(n + 5)*(n^2 + 25*n + 54)/30 - 1/5*(1 + ( - 1/2 - 1/2*5^(1/2))*cos(2*n*Pi/5) + ( - 3/10*2^(1/2)*(5 - 5^(1/2))^(1/2))*sin(2*n*Pi/5) + ( - 1/2 + 1/2*5^(1/2))*cos(4*n*Pi/5) + (3/10*2^(1/2)*(5 + 5^(1/2))^(1/2))*sin(4*n*Pi/5)) - Richard Choulet, Dec 14 2008
G.f. x^5*( 9-11*x+4*x^2+2*x^4-11*x^5+12*x^6-4*x^7 ) / ( (x^4+x^3+x^2+x+1)*(x-1)^4 ). - R. J. Mathar, Jun 23 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved