Boolean functions, again

[N. J. A. Sloane]

Thanks to Russ Cox, there's now (barely) enough terms
to put this sequence into the database: it is A056287.
Further progress will be recorded in that entry.

It would be nice to get one more term.

Using Russ's method, plus taking symmetries into account,
and using a large fast machine (or many machines), it
might be possible to find a(5).

This would seem to be a good candidate for a multiple-machine
project!

Neil Sloane