A125209 - OEIS

A125209

Irregular triangle read by rows: T(n,k) (n>=1, 0<=k<=n(n-1)/2) is such that Sum_k T(n,k)*p^(n*(n-1)/2-k) gives the expectation of the number of connected components after deleting every edge of the complete graph on n labeled vertices with probability p.

1, 1, 1, -1, 3, 0, 1, 2, -6, 3, 4, 0, 0, 1, -6, 20, -15, -10, 10, 0, 5, 0, 0, 0, 1, 24, -90, 90, 25, -60, 0, -5, 15, 0, 0, 6, 0, 0, 0, 0, 1, -120, 504, -630, 0, 420, -105, 0, -105, 0, 35, -21, 21, 0, 0, 0, 7, 0, 0, 0, 0, 0, 1, 720, -3360, 5040, -1176, -3150, 1680, 140, 560, -210, -280, 112

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OFFSET

1,5

COMMENTS

Row-reversed version of A125208, see A125208 for further details.

LINKS

Table of n, a(n) for n=1..74.

EXAMPLE

Triangle begins:

1, 1;

-1, 3, 0, 1;

2, -6, 3, 4, 0, 0, 1;