View Single Post
Old 2019-02-09, 22:34   #3
R. Gerbicz
 
R. Gerbicz's Avatar
 
"Robert Gerbicz"
Oct 2005
Hungary

2·3·11·23 Posts
Default

See https://oeis.org/A028444, this is a quite famous sequence, though it is giving much smaller lower bounds (check the sequences in the comment).

You are attacking very hard problems.
R. Gerbicz is offline   Reply With Quote