A054593 Number of disconnected labeled digraphs with n nodes.

0, 1, 10, 262, 21496, 6433336, 7566317200, 35247649746352, 648839620390462336, 47230175230392839683456, 13617860445102311268975051520, 15577054031612736747163633737901312

Offset

1,3

Links

Andrew Howroyd, Table of n, a(n) for n = 1..50

Formula

a(n) = 2^(n*(n-1)) - A003027(n).

Crossrefs

The unlabeled case is A054590.

Cf. A003027, A053763 (not necessarily connected), A054592.

Sequence in context: A084999 A268730 A217911 * A290041 A369423 A160481

Adjacent sequences: A054590 A054591 A054592 * A054594 A054595 A054596

Keyword

easy,nonn

Author

Vladeta Jovovic, Apr 15 2000

Status

approved