%I A133382
%S A133382 75,525,3940
%N A133382 Numbers n such that gcd( n!-1, 2^n-1 ) is neither 1 nor 2n+1.
%C A133382 This subsequence of A068483 lists the rare exceptions for which gcd( 
               N!, 2^N-1 ) <> 2N+1. Is it finite? Are all elements multiples of 
               5?
%o A133382 (PARI) for(n=1,10^5,if((g=gcd(n!-1,2^n-1)-1) & g!=2*n,print(n", ")))
%Y A133382 Cf. A068483, A068480.
%Y A133382 Sequence in context: A055561 A015223 A129625 this_sequence A017791 A017738 
               A166725
%Y A133382 Adjacent sequences: A133379 A133380 A133381 this_sequence A133383 A133384 
               A133385
%K A133382 nonn,bref
%O A133382 1,1
%A A133382 M. F. Hasler (Maximilian.Hasler(AT)gmail.com), Oct 28 2007