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A046751 Triangle read by rows of number of connected graphs with n nodes and k edges (n >= 2, 1 <= k <= n(n-1)/2). 5
1, 0, 1, 1, 0, 0, 2, 2, 1, 1, 0, 0, 0, 3, 5, 5, 4, 2, 1, 1, 0, 0, 0, 0, 6, 13, 19, 22, 20, 14, 9, 5, 2, 1, 1, 0, 0, 0, 0, 0, 11, 33, 67, 107, 132, 138, 126, 95, 64, 40, 21, 10, 5, 2, 1, 1, 0, 0, 0, 0, 0, 0, 23, 89, 236, 486, 814, 1169, 1454, 1579, 1515, 1290, 970, 658, 400, 220, 114 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,7

REFERENCES

G. A. Baker et al., High-temperature expansions for the spin-1/2 Heisenberg model, Phys. Rev., 164 (1967), 800-817.

LINKS

Table of n, a(n) for n=2..78.

Gordon Royle, Small graphs

Peter Steinbach, Field Guide to Simple Graphs, Volume 1, Part 17 (For Volumes 1, 2, 3, 4 of this book see A000088, A008406, A000055, A000664, respectively.)

EXAMPLE

1;

0,1,1;

0,0,2,2,1, 1;

0,0,0,3,5, 5, 4, 2,  1,  1;

0,0,0,0,6,13,19,22, 20, 14,  9,  5, 2, 1, 1;

0,0,0,0,0,11,33,67,107,132,138,126,95,64,40,21,10,5,2,1,1;

[ the 4th row giving the numbers of connected graphs with 4 nodes and from 1 to 10 edges ].

CROSSREFS

See A054924, which is the main entry for this triangle.

Cf. A002905, A008406, A046742, A054923, A054924.

Sequence in context: A246271 A049334 A054924 * A124478 A030353 A089617

Adjacent sequences:  A046748 A046749 A046750 * A046752 A046753 A046754

KEYWORD

nonn,easy,nice,tabf

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Vladeta Jovovic, Apr 21 2000

STATUS

approved

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Last modified December 12 16:06 EST 2018. Contains 318077 sequences. (Running on oeis4.)