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A049312 Number of graphs with a distinguished bipartite block, by number of vertices. 7
2, 4, 8, 17, 38, 94, 258, 815, 3038, 13804, 78760, 580456, 5647602, 73645352, 1297920850, 31031370360, 1007551636038, 44432872400460, 2661065508648436, 216457998880015366, 23920728651724212120, 3593384834863975164882 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Calculate number of connected bipartite graphs + number of connected bipartite graphs with no duality automorphism, apply EULER transform.

EULERi transform is also interesting

REFERENCES

R. W. Robinson, Numerical implementation of graph counting algorithms, AGRC Grant, Math. Dept., Univ. Newcastle, Australia, 1976.

LINKS

P. J. Cameron, Sequences realized by oligomorphic permutation groups, J. Integ. Seqs. Vol. 3 (2000), #00.1.5.

EXAMPLE

a(2)=4: null graph with 0, 1 or 2 vertices in the distinguished block and complete graph with 1 vertex in distinguished block.

CROSSREFS

Row sums of A028657.

Sequence in context: A090901 A101516 A118928 * A132043 A055545 A036375

Adjacent sequences:  A049309 A049310 A049311 * A049313 A049314 A049315

KEYWORD

nonn,nice

AUTHOR

Peter Cameron (p.j.cameron(AT)qmw.ac.uk)

EXTENSIONS

More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Jun 17 2000

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Last modified February 16 01:56 EST 2012. Contains 205860 sequences.