A005973 Number of connected labeled interval graphs with n nodes. (Formerly M3658)

1, 1, 4, 35, 541, 13062, 444767, 19912657, 1121041222, 77048430033, 6329916102841, 611728117464928, 68657066350744197, 8854866422322096893, 1300613343254300891316

Offset

1,3

References

P. J. Hanlon, personal communication.

R. W. Robinson, Numerical implementation of graph counting algorithms, AGRC Grant, Math. Dept., Univ. Newcastle, Australia, 1980.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

R. W. Robinson, Table of n, a(n) for n = 1..30

Phil Hanlon, Counting interval graphs, Trans. Amer. Math. Soc. 272 (1982), no. 2, 383-426.

Crossrefs

Sequence in context: A119391 A177387 A165933 * A007134 A334412 A238390

Adjacent sequences: A005970 A005971 A005972 * A005974 A005975 A005976

Keyword

nonn,nice

Author

N. J. A. Sloane

Status

approved