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A272361
Numbers n such that (2^n + 1) / gcd(n, 2^n + 1) is not squarefree.
2
182, 546, 910, 1274, 1638, 2002, 2366, 2730, 3094, 3458, 3822, 4186, 4550, 4914, 5278, 5642, 6006, 6370, 6734, 7098, 7462, 7826, 8190, 8554, 8918, 9282, 9646, 10010, 10374, 10738, 11102, 11466, 11830, 12194, 12558, 12922, 13286, 13650, 14014, 14378, 14742, 15106, 15470, 15834
OFFSET
1,1
COMMENTS
Odd multiples of integer A002326((q-1)/2)/2, where q is a Wieferich prime A001220.
PROG
(PARI) isok(n) = my(m=2^n+1); !issquarefree(m/gcd(n, m)); \\ Michel Marcus, Apr 27 2016
CROSSREFS
Sequence in context: A218563 A145297 A056091 * A158553 A015883 A043463
KEYWORD
nonn
AUTHOR
Thomas Ordowski, Apr 27 2016
STATUS
approved