A005381 - cp's OEIS frontend

A005381 Numbers k such that k and k-1 are composite.

n	a(n)
1	9
2	10
3	15
4	16
5	21
6	22
7	25
8	26
9	27
10	28
11	33
12	34
13	35
14	36
15	39
16	40
17	45
18	46
19	49
20	50
21	51
22	52
23	55
24	56
25	57
26	58
27	63
28	64
29	65
30	66
31	69
32	70
33	75
34	76
35	77
36	78
37	81
38	82
39	85
40	86
41	87
42	88
43	91
44	92
45	93
46	94
47	95
48	96
49	99
50	100
51	105
52	106
53	111
54	112
55	115
56	116
57	117
58	118
59	119
60	120
61	121
62	122

[9, 10, 15, 16, 21, 22, 25, 26, 27, 28, 33, 34, 35, 36, 39, 40, 45, 46, 49, 50, 51, 52, 55, 56, 57, 58, 63, 64, 65, 66, 69, 70, 75, 76, 77, 78, 81, 82, 85, 86, 87, 88, 91, 92, 93, 94, 95, 96, 99, 100, 105, 106, 111, 112, 115, 116, 117, 118, 119, 120, 121, 122]

cp's OEIS Frontend

A005381 Numbers k such that k and k-1 are composite.

Table of values

List of values

n	a(n)
1	9
2	10
3	15
4	16
5	21
6	22
7	25
8	26
9	27
10	28
11	33
12	34
13	35
14	36
15	39
16	40
17	45
18	46
19	49
20	50
21	51
22	52
23	55
24	56
25	57
26	58
27	63
28	64
29	65
30	66
31	69
32	70
33	75
34	76
35	77
36	78
37	81
38	82
39	85
40	86
41	87
42	88
43	91
44	92
45	93
46	94
47	95
48	96
49	99
50	100
51	105
52	106
53	111
54	112
55	115
56	116
57	117
58	118
59	119
60	120
61	121
62	122

n	a(n)
1	9
2	10
3	15
4	16
5	21
6	22
7	25
8	26
9	27
10	28
11	33
12	34
13	35
14	36
15	39
16	40
17	45
18	46
19	49
20	50
21	51
22	52
23	55
24	56
25	57
26	58
27	63
28	64
29	65
30	66
31	69
32	70
33	75
34	76
35	77
36	78
37	81
38	82
39	85
40	86
41	87
42	88
43	91
44	92
45	93
46	94
47	95
48	96
49	99
50	100
51	105
52	106
53	111
54	112
55	115
56	116
57	117
58	118
59	119
60	120
61	121
62	122

n	a(n)
1	9
2	10
3	15
4	16
5	21
6	22
7	25
8	26
9	27
10	28
11	33
12	34
13	35
14	36
15	39
16	40
17	45
18	46
19	49
20	50
21	51
22	52
23	55
24	56
25	57
26	58
27	63
28	64
29	65
30	66
31	69
32	70
33	75
34	76
35	77
36	78
37	81
38	82
39	85
40	86
41	87
42	88
43	91
44	92
45	93
46	94
47	95
48	96
49	99
50	100
51	105
52	106
53	111
54	112
55	115
56	116
57	117
58	118
59	119
60	120
61	121
62	122