A057957 - cp's OEIS frontend

A057957 Number of prime factors of 4^n - 1 (counted with multiplicity).

n	a(n)
1	1
2	2
3	3
4	3
5	3
6	5
7	3
8	4
9	6
10	6
11	4
12	7
13	3
14	6
15	7
16	5
17	3
18	10
19	3
20	8
21	8
22	7
23	4
24	10
25	7
26	7
27	9
28	8
29	6
30	13
31	3
32	7
33	9
34	7
35	9
36	14
37	5
38	7
39	8
40	10
41	5
42	14
43	5
44	10
45	13
46	9
47	6
48	13
49	5
50	14
51	11
52	10
53	6
54	15
55	12
56	11
57	9
58	9
59	6
60	17
61	3
62	8
63	14
64	9
65	9
66	15
67	5
68	11
69	9
70	16
71	6
72	19
73	6
74	10
75	14
76	11
77	10
78	18
79	5
80	13
81	16
82	10
83	8
84	19
85	7
86	10
87	11

[1, 2, 3, 3, 3, 5, 3, 4, 6, 6, 4, 7, 3, 6, 7, 5, 3, 10, 3, 8, 8, 7, 4, 10, 7, 7, 9, 8, 6, 13, 3, 7, 9, 7, 9, 14, 5, 7, 8, 10, 5, 14, 5, 10, 13, 9, 6, 13, 5, 14, 11, 10, 6, 15, 12, 11, 9, 9, 6, 17, 3, 8, 14, 9, 9, 15, 5, 11, 9, 16, 6, 19, 6, 10, 14, 11, 10, 18, 5, 13, 16, 10, 8, 19, 7, 10, 11]

cp's OEIS Frontend

A057957 Number of prime factors of 4^n - 1 (counted with multiplicity).

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	3
5	3
6	5
7	3
8	4
9	6
10	6
11	4
12	7
13	3
14	6
15	7
16	5
17	3
18	10
19	3
20	8
21	8
22	7
23	4
24	10
25	7
26	7
27	9
28	8
29	6
30	13
31	3
32	7
33	9
34	7
35	9
36	14
37	5
38	7
39	8
40	10
41	5
42	14
43	5
44	10
45	13
46	9
47	6
48	13
49	5
50	14
51	11
52	10
53	6
54	15
55	12
56	11
57	9
58	9
59	6
60	17
61	3
62	8
63	14
64	9
65	9
66	15
67	5
68	11
69	9
70	16
71	6
72	19
73	6
74	10
75	14
76	11
77	10
78	18
79	5
80	13
81	16
82	10
83	8
84	19
85	7
86	10
87	11

n	a(n)
1	1
2	2
3	3
4	3
5	3
6	5
7	3
8	4
9	6
10	6
11	4
12	7
13	3
14	6
15	7
16	5
17	3
18	10
19	3
20	8
21	8
22	7
23	4
24	10
25	7
26	7
27	9
28	8
29	6
30	13
31	3
32	7
33	9
34	7
35	9
36	14
37	5
38	7
39	8
40	10
41	5
42	14
43	5
44	10
45	13
46	9
47	6
48	13
49	5
50	14
51	11
52	10
53	6
54	15
55	12
56	11
57	9
58	9
59	6
60	17
61	3
62	8
63	14
64	9
65	9
66	15
67	5
68	11
69	9
70	16
71	6
72	19
73	6
74	10
75	14
76	11
77	10
78	18
79	5
80	13
81	16
82	10
83	8
84	19
85	7
86	10
87	11

n	a(n)
1	1
2	2
3	3
4	3
5	3
6	5
7	3
8	4
9	6
10	6
11	4
12	7
13	3
14	6
15	7
16	5
17	3
18	10
19	3
20	8
21	8
22	7
23	4
24	10
25	7
26	7
27	9
28	8
29	6
30	13
31	3
32	7
33	9
34	7
35	9
36	14
37	5
38	7
39	8
40	10
41	5
42	14
43	5
44	10
45	13
46	9
47	6
48	13
49	5
50	14
51	11
52	10
53	6
54	15
55	12
56	11
57	9
58	9
59	6
60	17
61	3
62	8
63	14
64	9
65	9
66	15
67	5
68	11
69	9
70	16
71	6
72	19
73	6
74	10
75	14
76	11
77	10
78	18
79	5
80	13
81	16
82	10
83	8
84	19
85	7
86	10
87	11