OFFSET
1,3
COMMENTS
Pollack and Pomerance showed that almost all squares are missing from the range of Euler's totient function.
LINKS
P. Pollack and C. Pomerance, Square values of Euler's function
EXAMPLE
PROG
(PARI) a(n) = {my(k = 1); while (!istotient((k*n)^2), k++); k; }
CROSSREFS
KEYWORD
nonn
AUTHOR
Altug Alkan, Jan 12 2017
STATUS
approved