[seqfan] Primitive pairs of powerful numbers

[Charles Greathouse]

Sequence A060355 has a simple proof of infinitude: each n in the
sequence generates 4n(n+1) also in the sequence.  This immediately
raises the question: are there infinitely many members not of this
form?  I recently added this as sequence A199801, primitive elements
of A060355.

Any good heuristics, if nothing else?

Charles Greathouse
Analyst/Programmer
Case Western Reserve University