a(n) is the smallest x such that sigma(x)/x = (3/2)*sigma(n)/n where sigma(n) is the sum of divisors of n or -1 if no such x exists.

A349717

a(n) is the smallest x such that sigma(x)/x = (3/2)*sigma(n)/n where sigma(n) is the sum of divisors of n or -1 if no such x exists.

Terms

    a(0) =2a(1) =40a(2) =6a(3) =96a(4) =10a(5) =120a(6) =14a(7) =6528a(8) =18a(9) =1120a(10) =22a(11) =4320a(12) =26a(13) =280a(14) =30a(15) =16896a(16) =34a(17) =360a(18) =38a(19) =480a(20) =42a(21) =440a(22) =46a(23) =293760a(24) =50a(25) =520a(26) =54a(27) =120a(28) =58a(29) =3360

External references