A325021 - cp's OEIS frontend

A325021 Harmonic numbers m from A001599 such that m*(m-tau(m))/sigma(m) is an integer h, where k-tau(k) is the number of nondivisors of k (A049820), tau(k) is the number of divisors of k (A000005), and sigma(k) is the sum of the divisors of k (A000203).

n	a(n)
1	1
2	6
3	28
4	496
5	672
6	8128
7	30240
8	32760
9	332640
10	695520
11	2178540
12	17428320
13	23569920
14	33550336
15	45532800
16	52141320
17	142990848
18	164989440
19	318729600
20	447828480
21	481572000
22	500860800
23	540277920
24	623397600
25	644271264
26	714954240
27	995248800
28	1047254400
29	1307124000

[1, 6, 28, 496, 672, 8128, 30240, 32760, 332640, 695520, 2178540, 17428320, 23569920, 33550336, 45532800, 52141320, 142990848, 164989440, 318729600, 447828480, 481572000, 500860800, 540277920, 623397600, 644271264, 714954240, 995248800, 1047254400, 1307124000]

cp's OEIS Frontend

A325021 Harmonic numbers m from A001599 such that m*(m-tau(m))/sigma(m) is an integer h, where k-tau(k) is the number of nondivisors of k (A049820), tau(k) is the number of divisors of k (A000005), and sigma(k) is the sum of the divisors of k (A000203).

Table of values

List of values