A057815 - cp's OEIS frontend

A057815 a(n) = gcd(n,binomial(n,floor(n/2))).

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

[1, 2, 3, 2, 5, 2, 7, 2, 9, 2, 11, 12, 13, 2, 15, 2, 17, 2, 19, 4, 21, 2, 23, 4, 25, 2, 27, 4, 29, 30, 31, 2, 33, 2, 35, 12, 37, 2, 39, 20, 41, 6, 43, 4, 45, 2, 47, 12, 49, 2, 51, 4, 53, 2, 55, 56, 57, 2, 59, 4, 61, 2, 63, 2, 65, 6, 67, 4, 69, 14, 71, 4, 73, 2, 75, 4, 77, 2, 79, 20, 81, 2]

cp's OEIS Frontend

A057815 a(n) = gcd(n,binomial(n,floor(n/2))).

Table of values

List of values

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

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

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