[seqfan] Max no. of edges in graph with no 4-cycles

[Neil Sloane]

Let b(n) be the maximum number of edges in a graph on n nodes that contains
no 4-cycle.

It seems to start (for n>=1) 0, 1, 3, 4, 7, 9?

Is it missing from the OEIS?


This question came up because M S Smith seems to have proved that b(n) is
an upper bound on Stan Wagon's Problem of the Week #1321 (and also on
A347301). Happy to send anyone who is interested a copy of Smith's email.


Best regards
Neil

Neil J. A. Sloane, Chairman, OEIS Foundation.
Also Visiting Scientist, Math. Dept., Rutgers University,
Email: njasloane at gmail.com