A332547 - cp's OEIS frontend

A332547 a(n) = largest odd divisor d < n of n*(n+1)/2.

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

[1, 1, 1, 1, 3, 3, 1, 3, 5, 5, 3, 3, 7, 7, 5, 1, 9, 9, 5, 15, 11, 11, 3, 15, 13, 13, 21, 7, 15, 15, 1, 11, 17, 17, 21, 9, 19, 19, 15, 5, 21, 21, 11, 33, 23, 23, 3, 21, 35, 25, 39, 13, 27, 45, 35, 21, 29, 29, 15, 15, 31, 31, 21, 13, 55, 33, 17, 51, 35, 35]

cp's OEIS Frontend

A332547 a(n) = largest odd divisor d < n of n*(n+1)/2.

Table of values

List of values

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

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

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