A034892 Number of balanced signed graphs on n unlabeled nodes.

1, 1, 3, 8, 39, 226, 2283, 36789, 1062679, 55717077, 5405078682, 972656526492, 325183692812200, 202373967993972497, 235081289816026793049, 511296223391186047847309, 2088912833728676472658628201, 16081914207958884651686215477871, 234010862353438997655954463710225233

Offset: 0

Author

Ronald C. Read

Keywords

• nonn
• nice

References

• R. C. Read and R. J. Wilson, An Atlas of Graphs, Oxford, 1998.

Links

• Andrew Howroyd, Table of n, a(n) for n = 0..50
• Wikipedia, Signed graph

Crossrefs

Cf. A004102, A005142, A318590.

Formula

Euler transform of A318590.

Extensions

Name clarified and offset corrected by Andrew Howroyd, Sep 25 2018

a(0)=1 prepended and terms a(13) and beyond from Andrew Howroyd, Sep 25 2018