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A127258 Triangular array read by rows: B(n,k) (n>=1, 0<=k<=n(n-1)/2) is such that SUM B(n,k)*q^(n*(n-1)/2-k) gives the expectation of the number of connected components in a random graph on n labeled vertices where every edge is present with probability q. 2
1, -1, 2, 1, 0, -3, 3, 2, -6, 3, 4, 0, -6, 4, -6, 40, -105, 130, -60, -18, 15, 10, 0, -10, 5, -24, 270, -1350, 3925, -7260, 8712, -6485, 2445, 60, -330, -18, 45, 20, 0, -15, 6, 120, -2016, 15750, -75810, 250950, -603435, 1084104, -1471305, 1502550, -1128820, 589281, -182721 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Row-reversed version of A125210, see A125210 for further details.

LINKS

Table of n, a(n) for n=1..53.

EXAMPLE

The array starts with

1

-1, 2

1, 0, -3, 3

2, -6, 3, 4, 0, -6, 4

-6, 40, -105, 130, -60, -18, 15, 10, 0, -10, 5

...

CROSSREFS

Cf. A125210 (row-reversed version), A125209 (dual version).

Sequence in context: A215063 A113020 A228821 * A154557 A049242 A108887

Adjacent sequences:  A127255 A127256 A127257 * A127259 A127260 A127261

KEYWORD

sign,tabf

AUTHOR

Max Alekseyev, Jan 09 2007

STATUS

approved

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Last modified December 21 18:51 EST 2014. Contains 252325 sequences.