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%I #20 Jan 28 2019 13:58:06
%S 182,546,910,1274,1638,2002,2366,2730,3094,3458,3822,4186,4550,4914,
%T 5278,5642,6006,6370,6734,7098,7462,7826,8190,8554,8918,9282,9646,
%U 10010,10374,10738,11102,11466,11830,12194,12558,12922,13286,13650,14014,14378,14742,15106,15470,15834
%N Numbers n such that (2^n + 1) / gcd(n, 2^n + 1) is not squarefree.
%C Odd multiples of integer A002326((q-1)/2)/2, where q is a Wieferich prime A001220.
%o (PARI) isok(n) = my(m=2^n+1); !issquarefree(m/gcd(n, m)); \\ _Michel Marcus_, Apr 27 2016
%Y Cf. A049096, A272359.
%K nonn
%O 1,1
%A _Thomas Ordowski_, Apr 27 2016