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A007834 Number of point labeled reduced 5-free two-graphs with n nodes. 0
1, 0, 1, 1, 16, 76, 1016, 10284, 157340, 2411756, 44953712, 899824256, 20283419872, 495216726096, 13202082981712, 378896535199888, 11690436112988224, 385173160930360192, 13509981115738946816 (list; graph; refs; listen; history; internal format)
OFFSET

1,5

LINKS

P. J. Cameron, Counting two-graphs related to trees, Elec. J. Combin., Vol. 2, #R4.

FORMULA

E.g.f.: -2*LambertW(-1/2*exp(-1/2)*(1+x)^(1/2))/(1+x). - Vladeta Jovovic (vladeta(AT)eunet.rs), Aug 21 2006

CROSSREFS

Sequence in context: A103111 A118862 A118532 * A200873 A082966 A198182

Adjacent sequences:  A007831 A007832 A007833 * A007835 A007836 A007837

KEYWORD

nonn

AUTHOR

Peter Cameron [ P.J.Cameron(AT)qmw.ac.uk ]

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Last modified February 16 16:25 EST 2012. Contains 205938 sequences.