A361725 - cp's OEIS frontend

A361725 a(n) is the largest of two middle prime factors of n if the number of prime divisors counted with multiplicity (A001222(n)) is even, otherwise is the middle prime factor of n.

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

[2, 3, 2, 5, 3, 7, 2, 3, 5, 11, 2, 13, 7, 5, 2, 17, 3, 19, 2, 7, 11, 23, 2, 5, 13, 3, 2, 29, 3, 31, 2, 11, 17, 7, 3, 37, 19, 13, 2, 41, 3, 43, 2, 3, 23, 47, 2, 7, 5, 17, 2, 53, 3, 11, 2, 19, 29, 59, 3, 61, 31, 3, 2, 13, 3, 67, 2, 23, 5, 71, 2, 73, 37, 5, 2, 11, 3]

cp's OEIS Frontend

A361725 a(n) is the largest of two middle prime factors of n if the number of prime divisors counted with multiplicity (A001222(n)) is even, otherwise is the middle prime factor of n.

Table of values

List of values

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

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

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