OFFSET
1,1
COMMENTS
There are no k for which (2^n)*(5^n)[p1*p2*...*pk]-2[p1*p2*...*pk]=m[(p1-1)*(p2-1)*...*(pk-1)].
Up to k = 60, the only totient of the form 10^k-2 is obtained for k=1. - Giovanni Resta, Sep 20 2017
For 10^k-2 with k > 1 to be a totient, it would have to be of the form (p-1)*p^m for some odd prime p and m >= 2. - Robert Israel, Sep 20 2017
EXAMPLE
CROSSREFS
KEYWORD
nonn
AUTHOR
Torlach Rush, Sep 18 2017
EXTENSIONS
More terms from Giovanni Resta, Sep 20 2017
STATUS
approved