OFFSET
0,3
COMMENTS
FORMULA
a(n) = Sum_{k=0..n} A101981(n-k)*C(n, k)^2.
PROG
(PARI) {a(n)=sum(k=0, n, sum(m=1, n, (-1)^(m-1)* (matrix(n+1, n+1, i, j, if(i>j, binomial(i-1, j-1)^2))^m/m)[n+1, k+1]))}
CROSSREFS
KEYWORD
sign
AUTHOR
Paul D. Hanna, Dec 23 2004
STATUS
approved