a(n) is the least number k such that the numerator of the harmonic mean of the divisors of k is equal to n, or -1 if no such k exists.
A348694
a(n) is the least number k such that the numerator of the harmonic mean of the divisors of k is equal to n, or -1 if no such k exists.
Terms
- a(0) =1a(1) =6a(2) =3a(3) =2a(4) =5a(5) =270a(6) =7a(7) =672a(8) =84a(9) =30a(10) =11a(11) =4a(12) =13a(13) =18620a(14) =420a(15) =24a(16) =17a(17) =12a(18) =19a(19) =10a(20) =21a(21) =22a(22) =23a(23) =30240a(24) =1550a(25) =78a(26) =9a(27) =168a(28) =29a(29) =60
External references
- oeis: A348694