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A320489
Number of connected nets on n unlabeled nodes.
4
1, 2, 6, 40, 581, 17954, 1376484, 275524246, 147627941386, 213261119287108, 836129127802137203, 8961301472286672235092, 264386586050074867407985650, 21609889100291959988235675761782, 4921292113269596022145447106163528469, 3138303995382684496665239674427115214538716
OFFSET
0,2
LINKS
Edward A. Bender and E. Rodney Canfield, Enumeration of connected invariant graphs, Journal of Combinatorial Theory, Series B 34.3 (1983): 268-278. See p. 274.
N. J. A. Sloane, Transforms
FORMULA
EULERi transform of A004103.
CROSSREFS
Cf. A004103.
Sequence in context: A238818 A199574 A379695 * A135755 A337699 A370615
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Oct 25 2018
EXTENSIONS
a(0)=1 prepended by Andrew Howroyd, Jan 26 2020
STATUS
approved