A056670 - cp's OEIS frontend

A056670 Largest non-unitary prime factor of A001405(n) = binomial(n, floor(n/2)), or 1 if no such prime exists.

n	a(n)
1	1
2	1
3	1
4	1
5	1
6	2
7	1
8	1
9	3
10	3
11	1
12	2
13	2
14	2
15	3
16	3
17	1
18	2
19	1
20	2
21	2
22	2
23	1
24	2
25	5
26	5
27	5
28	5
29	3
30	3
31	3
32	3
33	3
34	3
35	5
36	5
37	5
38	5
39	3
40	3
41	2
42	2
43	2
44	2
45	5
46	5
47	5
48	5
49	7
50	7
51	7
52	7
53	7
54	7
55	2
56	2
57	2
58	2
59	2
60	2
61	2
62	2
63	7
64	7
65	7
66	7
67	7
68	7
69	3
70	3
71	1
72	2
73	2
74	2
75	5
76	5
77	7
78	7
79	7
80	7
81	7
82	7
83	3
84	3
85	5
86	5
87	5
88	5
89	3
90	3
91	7
92	7
93	7
94	7
95	7
96	7
97	5
98	5
99	3
100	3
101	3
102	3
103	3
104	3
105	3

[1, 1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 2, 2, 2, 3, 3, 1, 2, 1, 2, 2, 2, 1, 2, 5, 5, 5, 5, 3, 3, 3, 3, 3, 3, 5, 5, 5, 5, 3, 3, 2, 2, 2, 2, 5, 5, 5, 5, 7, 7, 7, 7, 7, 7, 2, 2, 2, 2, 2, 2, 2, 2, 7, 7, 7, 7, 7, 7, 3, 3, 1, 2, 2, 2, 5, 5, 7, 7, 7, 7, 7, 7, 3, 3, 5, 5, 5, 5, 3, 3, 7, 7, 7, 7, 7, 7, 5, 5, 3, 3, 3, 3, 3, 3, 3]

cp's OEIS Frontend

A056670 Largest non-unitary prime factor of A001405(n) = binomial(n, floor(n/2)), or 1 if no such prime exists.

Table of values

List of values

n	a(n)
1	1
2	1
3	1
4	1
5	1
6	2
7	1
8	1
9	3
10	3
11	1
12	2
13	2
14	2
15	3
16	3
17	1
18	2
19	1
20	2
21	2
22	2
23	1
24	2
25	5
26	5
27	5
28	5
29	3
30	3
31	3
32	3
33	3
34	3
35	5
36	5
37	5
38	5
39	3
40	3
41	2
42	2
43	2
44	2
45	5
46	5
47	5
48	5
49	7
50	7
51	7
52	7
53	7
54	7
55	2
56	2
57	2
58	2
59	2
60	2
61	2
62	2
63	7
64	7
65	7
66	7
67	7
68	7
69	3
70	3
71	1
72	2
73	2
74	2
75	5
76	5
77	7
78	7
79	7
80	7
81	7
82	7
83	3
84	3
85	5
86	5
87	5
88	5
89	3
90	3
91	7
92	7
93	7
94	7
95	7
96	7
97	5
98	5
99	3
100	3
101	3
102	3
103	3
104	3
105	3

n	a(n)
1	1
2	1
3	1
4	1
5	1
6	2
7	1
8	1
9	3
10	3
11	1
12	2
13	2
14	2
15	3
16	3
17	1
18	2
19	1
20	2
21	2
22	2
23	1
24	2
25	5
26	5
27	5
28	5
29	3
30	3
31	3
32	3
33	3
34	3
35	5
36	5
37	5
38	5
39	3
40	3
41	2
42	2
43	2
44	2
45	5
46	5
47	5
48	5
49	7
50	7
51	7
52	7
53	7
54	7
55	2
56	2
57	2
58	2
59	2
60	2
61	2
62	2
63	7
64	7
65	7
66	7
67	7
68	7
69	3
70	3
71	1
72	2
73	2
74	2
75	5
76	5
77	7
78	7
79	7
80	7
81	7
82	7
83	3
84	3
85	5
86	5
87	5
88	5
89	3
90	3
91	7
92	7
93	7
94	7
95	7
96	7
97	5
98	5
99	3
100	3
101	3
102	3
103	3
104	3
105	3

n	a(n)
1	1
2	1
3	1
4	1
5	1
6	2
7	1
8	1
9	3
10	3
11	1
12	2
13	2
14	2
15	3
16	3
17	1
18	2
19	1
20	2
21	2
22	2
23	1
24	2
25	5
26	5
27	5
28	5
29	3
30	3
31	3
32	3
33	3
34	3
35	5
36	5
37	5
38	5
39	3
40	3
41	2
42	2
43	2
44	2
45	5
46	5
47	5
48	5
49	7
50	7
51	7
52	7
53	7
54	7
55	2
56	2
57	2
58	2
59	2
60	2
61	2
62	2
63	7
64	7
65	7
66	7
67	7
68	7
69	3
70	3
71	1
72	2
73	2
74	2
75	5
76	5
77	7
78	7
79	7
80	7
81	7
82	7
83	3
84	3
85	5
86	5
87	5
88	5
89	3
90	3
91	7
92	7
93	7
94	7
95	7
96	7
97	5
98	5
99	3
100	3
101	3
102	3
103	3
104	3
105	3