A034892 - OEIS

%I #8 Feb 20 2023 22:08:38

%S 1,1,3,8,39,226,2283,36789,1062679,55717077,5405078682,972656526492,

%T 325183692812200,202373967993972497,235081289816026793049,

%U 511296223391186047847309,2088912833728676472658628201,16081914207958884651686215477871,234010862353438997655954463710225233

%N Number of balanced signed graphs on n unlabeled nodes.

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

%H Andrew Howroyd, <a href="/A034892/b034892.txt">Table of n, a(n) for n = 0..50</a>

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Signed_graph">Signed graph</a>

%F Euler transform of A318590.

%Y Cf. A004102, A005142, A318590.

%K nonn,nice

%O 0,3

%A Ronald C. Read

%E Name clarified and offset corrected by _Andrew Howroyd_, Sep 25 2018

%E a(0)=1 prepended and terms a(13) and beyond from _Andrew Howroyd_, Sep 25 2018