A374897 - cp's OEIS frontend

A374897 a(n) is the least semiprime that ends with n, or -1 if there is no such semiprime.

n	a(n)
0	10
1	21
2	22
3	33
4	4
5	15
6	6
7	57
8	38
9	9
10	10
11	111
12	-1
13	213
14	14
15	15
16	-1
17	217
18	118
19	119
20	-1
21	21
22	22
23	123
24	-1
25	25
26	26
27	327
28	-1
29	129
30	-1
31	731
32	-1
33	33
34	34
35	35
36	-1
37	237
38	38
39	39
40	-1
41	141
42	142
43	143
44	-1
45	145
46	46
47	247
48	-1
49	49
50	-1
51	51
52	-1
53	253
54	254
55	55
56	-1
57	57
58	58
59	159
60	-1
61	161
62	62
63	763
64	-1
65	65
66	166
67	267
68	-1
69	69

[10, 21, 22, 33, 4, 15, 6, 57, 38, 9, 10, 111, -1, 213, 14, 15, -1, 217, 118, 119, -1, 21, 22, 123, -1, 25, 26, 327, -1, 129, -1, 731, -1, 33, 34, 35, -1, 237, 38, 39, -1, 141, 142, 143, -1, 145, 46, 247, -1, 49, -1, 51, -1, 253, 254, 55, -1, 57, 58, 159, -1, 161, 62, 763, -1, 65, 166, 267, -1, 69]

cp's OEIS Frontend

A374897 a(n) is the least semiprime that ends with n, or -1 if there is no such semiprime.

Table of values

List of values

n	a(n)
0	10
1	21
2	22
3	33
4	4
5	15
6	6
7	57
8	38
9	9
10	10
11	111
12	-1
13	213
14	14
15	15
16	-1
17	217
18	118
19	119
20	-1
21	21
22	22
23	123
24	-1
25	25
26	26
27	327
28	-1
29	129
30	-1
31	731
32	-1
33	33
34	34
35	35
36	-1
37	237
38	38
39	39
40	-1
41	141
42	142
43	143
44	-1
45	145
46	46
47	247
48	-1
49	49
50	-1
51	51
52	-1
53	253
54	254
55	55
56	-1
57	57
58	58
59	159
60	-1
61	161
62	62
63	763
64	-1
65	65
66	166
67	267
68	-1
69	69

n	a(n)
0	10
1	21
2	22
3	33
4	4
5	15
6	6
7	57
8	38
9	9
10	10
11	111
12	-1
13	213
14	14
15	15
16	-1
17	217
18	118
19	119
20	-1
21	21
22	22
23	123
24	-1
25	25
26	26
27	327
28	-1
29	129
30	-1
31	731
32	-1
33	33
34	34
35	35
36	-1
37	237
38	38
39	39
40	-1
41	141
42	142
43	143
44	-1
45	145
46	46
47	247
48	-1
49	49
50	-1
51	51
52	-1
53	253
54	254
55	55
56	-1
57	57
58	58
59	159
60	-1
61	161
62	62
63	763
64	-1
65	65
66	166
67	267
68	-1
69	69

n	a(n)
0	10
1	21
2	22
3	33
4	4
5	15
6	6
7	57
8	38
9	9
10	10
11	111
12	-1
13	213
14	14
15	15
16	-1
17	217
18	118
19	119
20	-1
21	21
22	22
23	123
24	-1
25	25
26	26
27	327
28	-1
29	129
30	-1
31	731
32	-1
33	33
34	34
35	35
36	-1
37	237
38	38
39	39
40	-1
41	141
42	142
43	143
44	-1
45	145
46	46
47	247
48	-1
49	49
50	-1
51	51
52	-1
53	253
54	254
55	55
56	-1
57	57
58	58
59	159
60	-1
61	161
62	62
63	763
64	-1
65	65
66	166
67	267
68	-1
69	69