A272361 Numbers n such that (2^n + 1) / gcd(n, 2^n + 1) is not squarefree.

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.

Links

Table of n, a(n) for n=1..44.

Prog

(PARI) isok(n) = my(m=2^n+1); !issquarefree(m/gcd(n, m)); \\ Michel Marcus, Apr 27 2016

Crossrefs

Cf. A049096, A272359.

Sequence in context: A218563 A145297 A056091 * A158553 A015883 A043463

Adjacent sequences: A272358 A272359 A272360 * A272362 A272363 A272364

Keyword

nonn

Author

Thomas Ordowski, Apr 27 2016

Status

approved