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%I #13 Oct 19 2017 03:14:32
%S 9,25,32,49,64,81,121,125,144
%N Numbers n such that for all k, (n^k-1)/(n-1) is not prime.
%C Indices of 0 in A084740.
%C Possibly a subset of A001597.
%C The first unknown value is n=152, checked up to k = prime(1100). - _Derek Orr_, Nov 29 2014
%C It is known 169, 216, 225, 243, 289, 324, 343 are also members of this sequence. - _Derek Orr_, Nov 29 2014
%Y Cf. A001597, A084738, A084740.
%K nonn,more
%O 1,1
%A _Amarnath Murthy_, Jun 17 2004
%E Edited by _Don Reble_, Mar 19 2007
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