OFFSET
1,2
FORMULA
T(n,m):=(n)!/(m)!*sum(k=0..n-m, k!*sum(i=k..n-m, (stirling1(i,k)*binomial(k,n-i-m))/i!)*m^k/k!).
EXAMPLE
1
2, 1,
6, 6, 1,
12, 36, 12, 1,
40, 180, 120, 20, 1,
60, 960, 1020, 300, 30, 1,
378, 4620, 8400, 3780, 630, 42, 1
PROG
(Maxima)
T(n, m):=(n)!/(m)!*sum(k!*sum((stirling1(i, k)*binomial(k, n-i-m))/i!, i, k, n-m)*m^k/k!, k, 0, n-m);
CROSSREFS
KEYWORD
sign,tabl
AUTHOR
Vladimir Kruchinin, Dec 14 2011
STATUS
approved