A304245 - cp's OEIS frontend

A304245 Numbers that yield a prime when '2' is inserted between the first and second digit, or prime(k+1) is inserted after the k-th digit for any k > 1, k < number of digits.

n	a(n)
1	0
2	1
3	2
4	3
5	4
6	5
7	6
8	7
9	8
10	9
11	17
12	23
13	27
14	29
15	41
16	51
17	53
18	77
19	81
20	83
21	87
22	89
23	99
24	101
25	113
26	129
27	149
28	159
29	179
30	191
31	203
32	213
33	221
34	237
35	251
36	267
37	269
38	273
39	281
40	287
41	293
42	297
43	321
44	329
45	357
46	359
47	401
48	417
49	419
50	429
51	441
52	461
53	471
54	497
55	509
56	531
57	561
58	581
59	603
60	611
61	663
62	669
63	687
64	699
65	707
66	711

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 17, 23, 27, 29, 41, 51, 53, 77, 81, 83, 87, 89, 99, 101, 113, 129, 149, 159, 179, 191, 203, 213, 221, 237, 251, 267, 269, 273, 281, 287, 293, 297, 321, 329, 357, 359, 401, 417, 419, 429, 441, 461, 471, 497, 509, 531, 561, 581, 603, 611, 663, 669, 687, 699, 707, 711]

cp's OEIS Frontend

A304245 Numbers that yield a prime when '2' is inserted between the first and second digit, or prime(k+1) is inserted after the k-th digit for any k > 1, k < number of digits.

Table of values

List of values

n	a(n)
1	0
2	1
3	2
4	3
5	4
6	5
7	6
8	7
9	8
10	9
11	17
12	23
13	27
14	29
15	41
16	51
17	53
18	77
19	81
20	83
21	87
22	89
23	99
24	101
25	113
26	129
27	149
28	159
29	179
30	191
31	203
32	213
33	221
34	237
35	251
36	267
37	269
38	273
39	281
40	287
41	293
42	297
43	321
44	329
45	357
46	359
47	401
48	417
49	419
50	429
51	441
52	461
53	471
54	497
55	509
56	531
57	561
58	581
59	603
60	611
61	663
62	669
63	687
64	699
65	707
66	711

n	a(n)
1	0
2	1
3	2
4	3
5	4
6	5
7	6
8	7
9	8
10	9
11	17
12	23
13	27
14	29
15	41
16	51
17	53
18	77
19	81
20	83
21	87
22	89
23	99
24	101
25	113
26	129
27	149
28	159
29	179
30	191
31	203
32	213
33	221
34	237
35	251
36	267
37	269
38	273
39	281
40	287
41	293
42	297
43	321
44	329
45	357
46	359
47	401
48	417
49	419
50	429
51	441
52	461
53	471
54	497
55	509
56	531
57	561
58	581
59	603
60	611
61	663
62	669
63	687
64	699
65	707
66	711

n	a(n)
1	0
2	1
3	2
4	3
5	4
6	5
7	6
8	7
9	8
10	9
11	17
12	23
13	27
14	29
15	41
16	51
17	53
18	77
19	81
20	83
21	87
22	89
23	99
24	101
25	113
26	129
27	149
28	159
29	179
30	191
31	203
32	213
33	221
34	237
35	251
36	267
37	269
38	273
39	281
40	287
41	293
42	297
43	321
44	329
45	357
46	359
47	401
48	417
49	419
50	429
51	441
52	461
53	471
54	497
55	509
56	531
57	561
58	581
59	603
60	611
61	663
62	669
63	687
64	699
65	707
66	711