

A123551


Triangle read by rows: T(n,k) (n >= 0, 0 <= k <= n(n1)/2) gives number of unlabeled graphs with endpoints on n node and k edges.


1



1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 2, 4, 3, 2, 1, 1, 1, 0, 0, 1, 1, 2, 6, 8, 13, 16, 13, 8, 5, 2, 1, 1, 1, 0, 0, 1, 1, 2, 6, 10, 22, 48, 76, 97, 102, 84, 60, 39, 20, 10, 5, 2, 1, 1, 1, 0, 0, 1, 1, 2, 6, 10, 25, 64, 152, 331, 617, 930, 1173, 1253, 1140
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OFFSET

0,21


REFERENCES

R. W. Robinson, Numerical implementation of graph counting algorithms, AGRC Grant, Math. Dept., Univ. Newcastle, Australia, 1977.


LINKS

R. W. Robinson, Rows 0 through 16, flattened


EXAMPLE

Triangle begins:
n = 0
k = 0 : 1
******************** total (n = 0) = 1
n = 1
k = 0 : 1
******************** total (n = 1) = 1
n = 2
k = 0 : 1
k = 1 : 0
******************** total (n = 2) = 1
n = 3
k = 0 : 1
k = 1 : 0
k = 2 : 0
k = 3 : 1
******************** total (n = 3) = 2
n = 4
k = 0 : 1
k = 1 : 0
k = 2 : 0
k = 3 : 1
k = 4 : 1
k = 5 : 1
k = 6 : 1
******************** total (n = 4) = 5


CROSSREFS

Sequence in context: A307500 A049245 A123547 * A286275 A029717 A135567
Adjacent sequences: A123548 A123549 A123550 * A123552 A123553 A123554


KEYWORD

nonn,tabf


AUTHOR

N. J. A. Sloane, Nov 14 2006


STATUS

approved



