OFFSET
1,2
FORMULA
a(n) = (280*n^12+1680*n^11-252*n^10-16660*n^9-13758*n^8+63408*n^7+68705*n^6-104265*n^5-111657*n^4+66997*n^3+56682*n^2-11160*n)/45360
Recurrence relation sum((-1)^k*binomial(13,k)*a(n-k), k= 0..13) = 0
GF(z) = z*(9+3631*z+115138*z^2+718465*z^3+1282314*z^4+718465*z^5+115138*z^6+ 3631*z^7+ 9*z^8)/(1-z)^13
MAPLE
nmax:=21; for n from 1 to nmax do RR(n) := expand(product((1-(2*k-1)^2*z)^(n-k+1), k=1..n), z) od: T:=1: for n from 1 to nmax do a(T):=coeff(-RR(n), z, 3): T:=T+1 od: seq(a(k), k=1..T-1);
CROSSREFS
Equals the absolute values of the coefficients that precede the a(n-3) factors of the recurrence relations RR(n) of A162011.
KEYWORD
easy,nonn
AUTHOR
Johannes W. Meijer, Jun 27 2009
STATUS
approved