A246970 Number of connected bicubical multigraphs on 2n labeled nodes of two colors.

1, 2, 31, 1272, 105720

Offset

1,2

Comments

Read's 1971 letter includes additional terms for both this sequence and A001500. But the terms a(6) and a(7) given for A001500 are wrong, so presumably those for this sequence are also wrong. See A246968 and A246969 for the sequences as given in Read's letter and (presumably) also in his dissertation.

References

R. C. Read, Some Enumeration Problems in Graph Theory. Ph.D. Dissertation, Department of Mathematics, Univ. London, 1958.

Links

Table of n, a(n) for n=1..5.

R. C. Read, Letter to N. J. A. Sloane, Feb 04 1971

Crossrefs

Cf. A001500, A246968, A246969.

Sequence in context: A224863 A263075 A217766 * A246969 A358567 A134646

Adjacent sequences: A246967 A246968 A246969 * A246971 A246972 A246973

Keyword

nonn,more

Author

N. J. A. Sloane, Sep 09 2014

Status

approved