login
A227533
Smallest e > 1 such that (2n)^e is a totient, or 0 if no such e exists.
4
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 4, 2, 3, 2, 2, 2, 4, 2, 2, 2, 2, 2, 3, 2, 5, 2, 2, 2, 2, 2, 2, 3, 3, 2, 4, 2, 15, 2, 2, 4, 2, 2, 3, 2, 3, 2, 4, 2, 2, 2, 2, 2, 3, 2, 7, 2, 2, 2, 2, 2, 2, 2, 4, 2, 3, 2, 2, 2, 2, 3, 3, 2, 8, 2, 2, 4, 15, 2, 2, 3, 2, 2, 5, 2, 4, 2, 2
OFFSET
1,1
COMMENTS
Conjecture: a(n) > 0 for all n.
LINKS
EXAMPLE
a(1) = 2 because phi(5) = 2^2. a(11) = 3 because phi(13315) = 22^3 but phi(k) is not equal to 22^2 for any k.
PROG
(PARI) a(n)=my(k=2); while(!istotient((2*n)^k), k++); k
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved