OFFSET
1,2
FORMULA
EXAMPLE
Triangle begins:
1;
2, -1;
3, -3, 0, 1;
4, -6, 0, 4, 3, -6, 2;
5, -10, 0, 10, 15, -18, -60, 130, -105, 40, -6;
...
Sum_k T(3,k)*q^k = 3-3*q+q^3 is the expectation of the number of connected components in a random graph on 3 labeled vertices where every edge is present with probability q.
PROG
(PARI) { H=sum(n=0, 6, x^n/(1-q)^(n*(n-1)/2)/n!); B=H*log(H); for(n=1, 6, print(Vecrev((1-q)^(n*(n-1)/2)*n!*polcoeff(B, n, x)))) }
CROSSREFS
KEYWORD
sign,tabf
AUTHOR
Max Alekseyev, Jan 09 2007
STATUS
approved