A227248 - cp's OEIS frontend

A227248 Composite numbers such that sum_{i=1..k} (p_i/(p_i+1))/product_{i=1..k} (p_i/(p_i+1)) is an integer, where p_i are the k prime factors of n (with multiplicity).

n	a(n)
1	4
2	72
3	102
4	216
5	260
6	264
7	270
8	432
9	462
10	504
11	612
12	720
13	1980
14	2592
15	3672
16	5184
17	5550
18	8352
19	10368
20	15552
21	20736
22	22032
23	25488
24	29016
25	30240
26	31104
27	36288
28	38880
29	41976
30	46656
31	49248
32	57888
33	62208
34	93312
35	103680
36	132192
37	186624
38	238464
39	286848
40	373248
41	410688

[4, 72, 102, 216, 260, 264, 270, 432, 462, 504, 612, 720, 1980, 2592, 3672, 5184, 5550, 8352, 10368, 15552, 20736, 22032, 25488, 29016, 30240, 31104, 36288, 38880, 41976, 46656, 49248, 57888, 62208, 93312, 103680, 132192, 186624, 238464, 286848, 373248, 410688]

cp's OEIS Frontend

A227248 Composite numbers such that sum_{i=1..k} (p_i/(p_i+1))/product_{i=1..k} (p_i/(p_i+1)) is an integer, where p_i are the k prime factors of n (with multiplicity).

Table of values

List of values