Search: id:A064234 Results 1-1 of 1 results found. %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 Search completed in 0.001 seconds