A213309 - cp's OEIS frontend

A213309 Numbers with exactly 2 nonprime substrings (substrings with leading zeros are considered to be nonprime).

n	a(n)
1	11
2	12
3	15
4	19
5	20
6	21
7	24
8	26
9	28
10	30
11	34
12	36
13	38
14	39
15	41
16	42
17	45
18	50
19	51
20	54
21	56
22	58
23	61
24	62
25	63
26	65
27	70
28	74
29	76
30	78
31	82
32	85
33	87
34	89
35	92
36	93
37	95
38	113
39	131
40	179
41	197
42	227
43	229
44	231
45	232
46	235
47	239
48	253
49	257
50	271
51	273
52	277
53	283

[11, 12, 15, 19, 20, 21, 24, 26, 28, 30, 34, 36, 38, 39, 41, 42, 45, 50, 51, 54, 56, 58, 61, 62, 63, 65, 70, 74, 76, 78, 82, 85, 87, 89, 92, 93, 95, 113, 131, 179, 197, 227, 229, 231, 232, 235, 239, 253, 257, 271, 273, 277, 283]

cp's OEIS Frontend

A213309 Numbers with exactly 2 nonprime substrings (substrings with leading zeros are considered to be nonprime).

Table of values

List of values

n	a(n)
1	11
2	12
3	15
4	19
5	20
6	21
7	24
8	26
9	28
10	30
11	34
12	36
13	38
14	39
15	41
16	42
17	45
18	50
19	51
20	54
21	56
22	58
23	61
24	62
25	63
26	65
27	70
28	74
29	76
30	78
31	82
32	85
33	87
34	89
35	92
36	93
37	95
38	113
39	131
40	179
41	197
42	227
43	229
44	231
45	232
46	235
47	239
48	253
49	257
50	271
51	273
52	277
53	283

n	a(n)
1	11
2	12
3	15
4	19
5	20
6	21
7	24
8	26
9	28
10	30
11	34
12	36
13	38
14	39
15	41
16	42
17	45
18	50
19	51
20	54
21	56
22	58
23	61
24	62
25	63
26	65
27	70
28	74
29	76
30	78
31	82
32	85
33	87
34	89
35	92
36	93
37	95
38	113
39	131
40	179
41	197
42	227
43	229
44	231
45	232
46	235
47	239
48	253
49	257
50	271
51	273
52	277
53	283

n	a(n)
1	11
2	12
3	15
4	19
5	20
6	21
7	24
8	26
9	28
10	30
11	34
12	36
13	38
14	39
15	41
16	42
17	45
18	50
19	51
20	54
21	56
22	58
23	61
24	62
25	63
26	65
27	70
28	74
29	76
30	78
31	82
32	85
33	87
34	89
35	92
36	93
37	95
38	113
39	131
40	179
41	197
42	227
43	229
44	231
45	232
46	235
47	239
48	253
49	257
50	271
51	273
52	277
53	283