OFFSET
2,2
COMMENTS
PROG
(PARI) {a(n)=if(n<1, 0, sum(k=1, n, abs(matrix(n, n, m, j, binomial(m-1, j-1)*binomial(m, j-1)/j)^-1)[n, k]))}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Feb 02 2005
STATUS
approved