

A112919


Number of nonisomorphic connected bipartite Hgraphs H(n:i,j;k,m) on 6n vertices (or nodes) for 1<=i,j,k,m<n/2.


3



0, 1, 0, 1, 0, 4, 0, 4, 0, 12, 0, 7, 0, 16, 0, 18, 0, 33, 0, 24, 0, 67, 0, 41, 0, 71, 0, 111
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OFFSET

3,6


COMMENTS

An Hgraph H(n:i,j;k,m) has 6n vertices arranged in six segments of n vertices. Let the vertices be v_{x,y} for x=0,1,2,3,4,5 and y in the integers modulo n. The edges are v_{0,y}v_{1,y}, v_{0,y}v_{2,y}, v_{0,y}v_{3,y}, v_{1,y}v_{4,y}, v_{1,y}v_{5,y} (inner edges) and v_{2,y}v_{2,y+i}, v_{3,y}v_{3,y+j}, v_{4,y}v_{3,y+k}, v_{5,y}v_{5,y+m} (outer edges) where y=0,1,...,n1 and subscript addition is performed modulo n.


REFERENCES

I. Z. Bouwer, W. W. Chernoff, B. Monson, and Z. Starr (Editors), "Foster's Census", Charles Babbage Research Centre, Winnipeg, 1988.


LINKS



EXAMPLE

The only connected symmetric bipartite Hgraph is H(34:1,13;9,15) which is also listed in Foster's Census.


CROSSREFS



KEYWORD

nonn,more


AUTHOR

Marko Boben (Marko.Boben(AT)fmf.unilj.si), Tomaz Pisanski and Arjana Zitnik (Arjana.Zitnik(AT)fmf.unilj.si), Oct 06 2005


STATUS

approved



