A089653 - cp's OEIS frontend

A089653 Numbers k > 1 such that (product of prime factors of k) - 1 is a perfect square.

n	a(n)
1	2
2	4
3	5
4	8
5	10
6	16
7	17
8	20
9	25
10	26
11	32
12	37
13	40
14	50
15	52
16	64
17	65
18	80
19	82
20	100
21	101
22	104
23	122
24	125
25	128
26	145
27	160
28	164
29	170
30	197
31	200
32	208
33	226
34	244
35	250
36	256
37	257
38	289
39	290
40	320
41	325
42	328
43	338
44	340
45	362
46	400
47	401
48	416
49	442
50	452
51	485
52	488
53	500
54	512
55	530
56	577
57	580

[2, 4, 5, 8, 10, 16, 17, 20, 25, 26, 32, 37, 40, 50, 52, 64, 65, 80, 82, 100, 101, 104, 122, 125, 128, 145, 160, 164, 170, 197, 200, 208, 226, 244, 250, 256, 257, 289, 290, 320, 325, 328, 338, 340, 362, 400, 401, 416, 442, 452, 485, 488, 500, 512, 530, 577, 580]

cp's OEIS Frontend

A089653 Numbers k > 1 such that (product of prime factors of k) - 1 is a perfect square.

Table of values

List of values

n	a(n)
1	2
2	4
3	5
4	8
5	10
6	16
7	17
8	20
9	25
10	26
11	32
12	37
13	40
14	50
15	52
16	64
17	65
18	80
19	82
20	100
21	101
22	104
23	122
24	125
25	128
26	145
27	160
28	164
29	170
30	197
31	200
32	208
33	226
34	244
35	250
36	256
37	257
38	289
39	290
40	320
41	325
42	328
43	338
44	340
45	362
46	400
47	401
48	416
49	442
50	452
51	485
52	488
53	500
54	512
55	530
56	577
57	580

n	a(n)
1	2
2	4
3	5
4	8
5	10
6	16
7	17
8	20
9	25
10	26
11	32
12	37
13	40
14	50
15	52
16	64
17	65
18	80
19	82
20	100
21	101
22	104
23	122
24	125
25	128
26	145
27	160
28	164
29	170
30	197
31	200
32	208
33	226
34	244
35	250
36	256
37	257
38	289
39	290
40	320
41	325
42	328
43	338
44	340
45	362
46	400
47	401
48	416
49	442
50	452
51	485
52	488
53	500
54	512
55	530
56	577
57	580

n	a(n)
1	2
2	4
3	5
4	8
5	10
6	16
7	17
8	20
9	25
10	26
11	32
12	37
13	40
14	50
15	52
16	64
17	65
18	80
19	82
20	100
21	101
22	104
23	122
24	125
25	128
26	145
27	160
28	164
29	170
30	197
31	200
32	208
33	226
34	244
35	250
36	256
37	257
38	289
39	290
40	320
41	325
42	328
43	338
44	340
45	362
46	400
47	401
48	416
49	442
50	452
51	485
52	488
53	500
54	512
55	530
56	577
57	580