A336509 - cp's OEIS frontend

A336509 Even squarefree numbers k such that d_{i+1}/d_i < 2 for all 1 < i < tau(k) - 1, where 1 = d_1 < d_2 < ... < d_tau(k) = k are the divisors of k, and tau(k) is their number (A000005).

n	a(n)
1	6
2	30
3	210
4	330
5	390
6	510
7	570
8	690
9	870
10	2310
11	2730
12	3570
13	3990
14	4290
15	4830
16	5610
17	6090
18	6270
19	6510
20	6630
21	7410
22	7590
23	7770
24	8610
25	8970
26	9030
27	9570
28	9690
29	9870
30	10230
31	11130
32	11310
33	11730
34	12090
35	12210
36	12390
37	12810
38	13110
39	13530
40	14070
41	14190
42	14430
43	14790
44	14910

[6, 30, 210, 330, 390, 510, 570, 690, 870, 2310, 2730, 3570, 3990, 4290, 4830, 5610, 6090, 6270, 6510, 6630, 7410, 7590, 7770, 8610, 8970, 9030, 9570, 9690, 9870, 10230, 11130, 11310, 11730, 12090, 12210, 12390, 12810, 13110, 13530, 14070, 14190, 14430, 14790, 14910]

cp's OEIS Frontend

A336509 Even squarefree numbers k such that d_{i+1}/d_i < 2 for all 1 < i < tau(k) - 1, where 1 = d_1 < d_2 < ... < d_tau(k) = k are the divisors of k, and tau(k) is their number (A000005).

Table of values

List of values