a(n) = numerator of Sum_{1 <= i < j <= d(n)} 1/(d_j - d_i), sum over ordered pairs of divisors of n, where d(n) is the number of divisors of n.
A330077
a(n) = numerator of Sum_{1 <= i < j <= d(n)} 1/(d_j - d_i), sum over ordered pairs of divisors of n, where d(n) is the number of divisors of n.
Terms
- a(0) =0a(1) =1a(2) =1a(3) =11a(4) =1a(5) =197a(6) =1a(7) =67a(8) =19a(9) =727a(10) =1a(11) =24593a(12) =1a(13) =3039a(14) =158a(15) =767a(16) =1a(17) =379873a(18) =1a(19) =19867a(20) =689a(21) =19399a(22) =1a(23) =3446147a(24) =41a(25) =38119a(26) =217a(27) =311809a(28) =1a(29) =1817969
External references
- oeis: A330077