OFFSET
1,1
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
PROG
(PARI) isok(n) = my(m=2^n-1); !issquarefree(m/gcd(n, m)); \\ Michel Marcus, Apr 27 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Thomas Ordowski, Apr 27 2016
STATUS
approved