A085776 - cp's OEIS frontend

A085776 Numbers k such that k concatenated with k+1 is a semiprime.

n	a(n)
1	3
2	10
3	14
4	17
5	18
6	20
7	21
8	26
9	30
10	32
11	33
12	38
13	45
14	46
15	48
16	53
17	54
18	57
19	66
20	70
21	72
22	77
23	81
24	84
25	88
26	98
27	101
28	105
29	110
30	116
31	118
32	122
33	125
34	128
35	132
36	140
37	141
38	142
39	146
40	152
41	158
42	162
43	164
44	170
45	173
46	176
47	177
48	178
49	185
50	190
51	194
52	198
53	204
54	206
55	208
56	210
57	212
58	218
59	222

[3, 10, 14, 17, 18, 20, 21, 26, 30, 32, 33, 38, 45, 46, 48, 53, 54, 57, 66, 70, 72, 77, 81, 84, 88, 98, 101, 105, 110, 116, 118, 122, 125, 128, 132, 140, 141, 142, 146, 152, 158, 162, 164, 170, 173, 176, 177, 178, 185, 190, 194, 198, 204, 206, 208, 210, 212, 218, 222]

cp's OEIS Frontend

A085776 Numbers k such that k concatenated with k+1 is a semiprime.

Table of values

List of values

n	a(n)
1	3
2	10
3	14
4	17
5	18
6	20
7	21
8	26
9	30
10	32
11	33
12	38
13	45
14	46
15	48
16	53
17	54
18	57
19	66
20	70
21	72
22	77
23	81
24	84
25	88
26	98
27	101
28	105
29	110
30	116
31	118
32	122
33	125
34	128
35	132
36	140
37	141
38	142
39	146
40	152
41	158
42	162
43	164
44	170
45	173
46	176
47	177
48	178
49	185
50	190
51	194
52	198
53	204
54	206
55	208
56	210
57	212
58	218
59	222

n	a(n)
1	3
2	10
3	14
4	17
5	18
6	20
7	21
8	26
9	30
10	32
11	33
12	38
13	45
14	46
15	48
16	53
17	54
18	57
19	66
20	70
21	72
22	77
23	81
24	84
25	88
26	98
27	101
28	105
29	110
30	116
31	118
32	122
33	125
34	128
35	132
36	140
37	141
38	142
39	146
40	152
41	158
42	162
43	164
44	170
45	173
46	176
47	177
48	178
49	185
50	190
51	194
52	198
53	204
54	206
55	208
56	210
57	212
58	218
59	222

n	a(n)
1	3
2	10
3	14
4	17
5	18
6	20
7	21
8	26
9	30
10	32
11	33
12	38
13	45
14	46
15	48
16	53
17	54
18	57
19	66
20	70
21	72
22	77
23	81
24	84
25	88
26	98
27	101
28	105
29	110
30	116
31	118
32	122
33	125
34	128
35	132
36	140
37	141
38	142
39	146
40	152
41	158
42	162
43	164
44	170
45	173
46	176
47	177
48	178
49	185
50	190
51	194
52	198
53	204
54	206
55	208
56	210
57	212
58	218
59	222