A373575 - cp's OEIS frontend

A373575 Numbers k such that k and k-1 both have at least two distinct prime factors. First element of the n-th maximal antirun of non-prime-powers.

n	a(n)
1	1
2	15
3	21
4	22
5	34
6	35
7	36
8	39
9	40
10	45
11	46
12	51
13	52
14	55
15	56
16	57
17	58
18	63
19	66
20	69
21	70
22	75
23	76
24	77
25	78
26	85
27	86
28	87
29	88
30	91
31	92
32	93
33	94
34	95
35	96
36	99
37	100
38	105
39	106
40	111
41	112
42	115
43	116
44	117
45	118
46	119
47	120
48	123
49	124
50	130
51	133
52	134
53	135
54	136
55	141
56	142
57	143
58	144
59	145

[1, 15, 21, 22, 34, 35, 36, 39, 40, 45, 46, 51, 52, 55, 56, 57, 58, 63, 66, 69, 70, 75, 76, 77, 78, 85, 86, 87, 88, 91, 92, 93, 94, 95, 96, 99, 100, 105, 106, 111, 112, 115, 116, 117, 118, 119, 120, 123, 124, 130, 133, 134, 135, 136, 141, 142, 143, 144, 145]

cp's OEIS Frontend

A373575 Numbers k such that k and k-1 both have at least two distinct prime factors. First element of the n-th maximal antirun of non-prime-powers.

Table of values

List of values

n	a(n)
1	1
2	15
3	21
4	22
5	34
6	35
7	36
8	39
9	40
10	45
11	46
12	51
13	52
14	55
15	56
16	57
17	58
18	63
19	66
20	69
21	70
22	75
23	76
24	77
25	78
26	85
27	86
28	87
29	88
30	91
31	92
32	93
33	94
34	95
35	96
36	99
37	100
38	105
39	106
40	111
41	112
42	115
43	116
44	117
45	118
46	119
47	120
48	123
49	124
50	130
51	133
52	134
53	135
54	136
55	141
56	142
57	143
58	144
59	145

n	a(n)
1	1
2	15
3	21
4	22
5	34
6	35
7	36
8	39
9	40
10	45
11	46
12	51
13	52
14	55
15	56
16	57
17	58
18	63
19	66
20	69
21	70
22	75
23	76
24	77
25	78
26	85
27	86
28	87
29	88
30	91
31	92
32	93
33	94
34	95
35	96
36	99
37	100
38	105
39	106
40	111
41	112
42	115
43	116
44	117
45	118
46	119
47	120
48	123
49	124
50	130
51	133
52	134
53	135
54	136
55	141
56	142
57	143
58	144
59	145

n	a(n)
1	1
2	15
3	21
4	22
5	34
6	35
7	36
8	39
9	40
10	45
11	46
12	51
13	52
14	55
15	56
16	57
17	58
18	63
19	66
20	69
21	70
22	75
23	76
24	77
25	78
26	85
27	86
28	87
29	88
30	91
31	92
32	93
33	94
34	95
35	96
36	99
37	100
38	105
39	106
40	111
41	112
42	115
43	116
44	117
45	118
46	119
47	120
48	123
49	124
50	130
51	133
52	134
53	135
54	136
55	141
56	142
57	143
58	144
59	145