%I A064234
%S A064234 1,3,28,5,66,7,232,45,190,11,276,13,1106,0,286,17,1854,19,3820,891,
%T A064234 2752,23,1128,595,2046,0,532,29,1770,31,9952,425,1288,0,2486,37,8474,0,
%U A064234 742,41,3486,43,7612,5589,2356,47,13584,325,9850,0,20554,53,5778
%N A064234 The least k such that {A063994} Product_{primes p dividing k } gcd(p-1, 
               k-1) = n, or 0 if impossible.
%t A064234 f[ n_ ] := If[ n == 1, 1, Apply[ Times, GCD[ n - 1, Transpose[ FactorInteger[ 
               n ] ] [ [ 1 ] ] - 1 ] ] ]; a = Table[ 0, {100} ]; Do[ m = f[ n ]; 
               If[ m < 101 && a[ [ m ] ] == 0, a[ [ m ] ] = n ], {n, 1, 10^7} ]; 
               a a(54) > 2*10^7. The zeros appear at positions that are the values 
               in the sequence A005277, the nontotients: even n such that phi(m) 
               = n has no solution.
%Y A064234 Cf. A063994 and A005277.
%Y A064234 Sequence in context: A071107 A146072 A073049 this_sequence A037102 A042169 
               A041785
%Y A064234 Adjacent sequences: A064231 A064232 A064233 this_sequence A064235 A064236 
               A064237
%K A064234 nonn
%O A064234 1,2
%A A064234 Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 22 2001