OFFSET
1,1
COMMENTS
EXAMPLE
4934 = 2*2467 is a term because psi(4934)*phi(4934) = (2^2 - 1)*(2467^2 - 1) = 2^3*3^3*137*617 is not a totient number (A002202).
CROSSREFS
KEYWORD
nonn
AUTHOR
Altug Alkan, Sep 21 2017
STATUS
approved