A023520 - cp's OEIS frontend

A023520 Exponent of 2 in prime factorization of prime(n)*prime(n-1) - 1.

n	a(n)
2	0
3	1
4	1
5	2
6	1
7	2
8	1
9	2
10	1
11	1
12	1
13	2
14	1
15	2
16	1
17	1
18	1
19	1
20	2
21	1
22	1
23	2
24	1
25	3
26	2
27	1
28	2
29	1
30	2
31	1
32	2
33	1
34	1
35	1
36	1
37	1
38	1
39	2
40	1
41	1
42	1
43	1
44	1
45	2
46	1
47	2
48	2
49	2
50	1
51	2
52	1
53	1
54	1
55	1
56	1
57	1
58	1
59	1
60	2
61	1
62	1
63	1
64	2
65	1
66	2
67	1
68	1
69	1
70	1
71	2
72	1
73	3
74	1
75	1
76	2
77	1
78	6
79	2
80	3

[0, 1, 1, 2, 1, 2, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 2, 1, 1, 2, 1, 3, 2, 1, 2, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 2, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 2, 1, 3, 1, 1, 2, 1, 6, 2, 3]

cp's OEIS Frontend

A023520 Exponent of 2 in prime factorization of prime(n)*prime(n-1) - 1.

Table of values

List of values

n	a(n)
2	0
3	1
4	1
5	2
6	1
7	2
8	1
9	2
10	1
11	1
12	1
13	2
14	1
15	2
16	1
17	1
18	1
19	1
20	2
21	1
22	1
23	2
24	1
25	3
26	2
27	1
28	2
29	1
30	2
31	1
32	2
33	1
34	1
35	1
36	1
37	1
38	1
39	2
40	1
41	1
42	1
43	1
44	1
45	2
46	1
47	2
48	2
49	2
50	1
51	2
52	1
53	1
54	1
55	1
56	1
57	1
58	1
59	1
60	2
61	1
62	1
63	1
64	2
65	1
66	2
67	1
68	1
69	1
70	1
71	2
72	1
73	3
74	1
75	1
76	2
77	1
78	6
79	2
80	3

n	a(n)
2	0
3	1
4	1
5	2
6	1
7	2
8	1
9	2
10	1
11	1
12	1
13	2
14	1
15	2
16	1
17	1
18	1
19	1
20	2
21	1
22	1
23	2
24	1
25	3
26	2
27	1
28	2
29	1
30	2
31	1
32	2
33	1
34	1
35	1
36	1
37	1
38	1
39	2
40	1
41	1
42	1
43	1
44	1
45	2
46	1
47	2
48	2
49	2
50	1
51	2
52	1
53	1
54	1
55	1
56	1
57	1
58	1
59	1
60	2
61	1
62	1
63	1
64	2
65	1
66	2
67	1
68	1
69	1
70	1
71	2
72	1
73	3
74	1
75	1
76	2
77	1
78	6
79	2
80	3

n	a(n)
2	0
3	1
4	1
5	2
6	1
7	2
8	1
9	2
10	1
11	1
12	1
13	2
14	1
15	2
16	1
17	1
18	1
19	1
20	2
21	1
22	1
23	2
24	1
25	3
26	2
27	1
28	2
29	1
30	2
31	1
32	2
33	1
34	1
35	1
36	1
37	1
38	1
39	2
40	1
41	1
42	1
43	1
44	1
45	2
46	1
47	2
48	2
49	2
50	1
51	2
52	1
53	1
54	1
55	1
56	1
57	1
58	1
59	1
60	2
61	1
62	1
63	1
64	2
65	1
66	2
67	1
68	1
69	1
70	1
71	2
72	1
73	3
74	1
75	1
76	2
77	1
78	6
79	2
80	3