A007110 Number of connected labeled 2-regular oriented graphs with n nodes. (Formerly M5163)

0, 0, 0, 0, 0, 24, 570, 27900, 1827630, 152031600, 15453811800, 1884214710000, 271711218933000, 45788138466285600, 8922341314806519600, 1991726163596104135200, 505133470313552174094000

Offset

0,6

References

R. W. Robinson, personal communication.

R. W. Robinson, Numerical implementation of graph counting algorithms, AGRC Grant, Math. Dept., Univ. Newcastle, Australia, 1982.

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 = 0..48

Crossrefs

Sequence in context: A170743 A218726 A203487 * A007109 A158538 A171329

Adjacent sequences: A007107 A007108 A007109 * A007111 A007112 A007113

Keyword

nonn,nice

Author

N. J. A. Sloane

Status

approved