A375511 - cp's OEIS frontend

A375511 a(n) is the common difference in the longest arithmetic progression of semiprimes ending in the n-th semiprime. If there is more than one such arithmetic progression, the smallest difference is chosen.

n	a(n)
2	2
3	3
4	1
5	4
6	1
7	6
8	8
9	3
10	11
11	12
12	12
13	1
14	12
15	1
16	12
17	14
18	13
19	17
20	11
21	12
22	24
23	7
24	18
25	35
26	19
27	24
28	8
29	24
30	18
31	29
32	8
33	36
34	1
35	24
36	17
37	30
38	12
39	4
40	3
41	48
42	4
43	36
44	11
45	48
46	23
47	24
48	1
49	30
50	12
51	13
52	12
53	36
54	42
55	24
56	14
57	16
58	36
59	14
60	8
61	32
62	36
63	7
64	60
65	42
66	60
67	60
68	3
69	4
70	36
71	46
72	4
73	12
74	32
75	4
76	60
77	16
78	18
79	44
80	36
81	16

[2, 3, 1, 4, 1, 6, 8, 3, 11, 12, 12, 1, 12, 1, 12, 14, 13, 17, 11, 12, 24, 7, 18, 35, 19, 24, 8, 24, 18, 29, 8, 36, 1, 24, 17, 30, 12, 4, 3, 48, 4, 36, 11, 48, 23, 24, 1, 30, 12, 13, 12, 36, 42, 24, 14, 16, 36, 14, 8, 32, 36, 7, 60, 42, 60, 60, 3, 4, 36, 46, 4, 12, 32, 4, 60, 16, 18, 44, 36, 16]

cp's OEIS Frontend

A375511 a(n) is the common difference in the longest arithmetic progression of semiprimes ending in the n-th semiprime. If there is more than one such arithmetic progression, the smallest difference is chosen.

Table of values

List of values

n	a(n)
2	2
3	3
4	1
5	4
6	1
7	6
8	8
9	3
10	11
11	12
12	12
13	1
14	12
15	1
16	12
17	14
18	13
19	17
20	11
21	12
22	24
23	7
24	18
25	35
26	19
27	24
28	8
29	24
30	18
31	29
32	8
33	36
34	1
35	24
36	17
37	30
38	12
39	4
40	3
41	48
42	4
43	36
44	11
45	48
46	23
47	24
48	1
49	30
50	12
51	13
52	12
53	36
54	42
55	24
56	14
57	16
58	36
59	14
60	8
61	32
62	36
63	7
64	60
65	42
66	60
67	60
68	3
69	4
70	36
71	46
72	4
73	12
74	32
75	4
76	60
77	16
78	18
79	44
80	36
81	16

n	a(n)
2	2
3	3
4	1
5	4
6	1
7	6
8	8
9	3
10	11
11	12
12	12
13	1
14	12
15	1
16	12
17	14
18	13
19	17
20	11
21	12
22	24
23	7
24	18
25	35
26	19
27	24
28	8
29	24
30	18
31	29
32	8
33	36
34	1
35	24
36	17
37	30
38	12
39	4
40	3
41	48
42	4
43	36
44	11
45	48
46	23
47	24
48	1
49	30
50	12
51	13
52	12
53	36
54	42
55	24
56	14
57	16
58	36
59	14
60	8
61	32
62	36
63	7
64	60
65	42
66	60
67	60
68	3
69	4
70	36
71	46
72	4
73	12
74	32
75	4
76	60
77	16
78	18
79	44
80	36
81	16

n	a(n)
2	2
3	3
4	1
5	4
6	1
7	6
8	8
9	3
10	11
11	12
12	12
13	1
14	12
15	1
16	12
17	14
18	13
19	17
20	11
21	12
22	24
23	7
24	18
25	35
26	19
27	24
28	8
29	24
30	18
31	29
32	8
33	36
34	1
35	24
36	17
37	30
38	12
39	4
40	3
41	48
42	4
43	36
44	11
45	48
46	23
47	24
48	1
49	30
50	12
51	13
52	12
53	36
54	42
55	24
56	14
57	16
58	36
59	14
60	8
61	32
62	36
63	7
64	60
65	42
66	60
67	60
68	3
69	4
70	36
71	46
72	4
73	12
74	32
75	4
76	60
77	16
78	18
79	44
80	36
81	16