A063513 - OEIS

%I #14 Aug 24 2019 12:28:56

%S 3,2,56,12,2580,630,416640,291060,1719277560,587133466920,33044291280

%N Least balanced numbers (A020492): m such that the quotient sigma(m)/phi(m) equals the n-th prime.

%F a(n) = Min{x : A000203(x)/A000010(x) = p(n)} = Min{x : A023897(x) = p(n)}

%e n=7: p(7) = 17. a(7) = 416640 = 2^7*3*5*7*31. sigma(416640) = 1566720 = 17*phi(a(7)). phi(416640) = 92160.

%Y Cf. A055234 (smallest x such that sigma(x) = n*phi(x)), A000203, A000010, A020492, A023897.

%K nonn,more

%O 1,1

%A _Labos Elemer_, Jul 31 2001

%E More terms from _Robert G. Wilson v_, Aug 09 2001

%E a(10)-a(11) (from A055234) added by _Donovan Johnson_, Feb 03 2012