A226853 - cp's OEIS frontend

A226853 Numbers n such that Sum_{i = 1..q} 1/d(i) is an integer where d(i) are the divisors of n for some q and n is primitive (the set {d(1), d(2), ..., d(q)} appears only once).

n	a(n)
1	1
2	6
3	28
4	120
5	180
6	496
7	672
8	1890
9	8128
10	8415
11	20482
12	20496
13	25410
14	30240
15	32760
16	33345
17	34155
18	38430
19	40128
20	47804
21	72800
22	90720
23	103530
24	407715
25	523776
26	806190
27	979992
28	1084160
29	1273725
30	1274100
31	2178540
32	3571050
33	7441280
34	10782216
35	12499150
36	23569920
37	28360464
38	33550336
39	45532800

[1, 6, 28, 120, 180, 496, 672, 1890, 8128, 8415, 20482, 20496, 25410, 30240, 32760, 33345, 34155, 38430, 40128, 47804, 72800, 90720, 103530, 407715, 523776, 806190, 979992, 1084160, 1273725, 1274100, 2178540, 3571050, 7441280, 10782216, 12499150, 23569920, 28360464, 33550336, 45532800]

cp's OEIS Frontend

A226853 Numbers n such that Sum_{i = 1..q} 1/d(i) is an integer where d(i) are the divisors of n for some q and n is primitive (the set {d(1), d(2), ..., d(q)} appears only once).

Table of values

List of values