A252489 - cp's OEIS frontend

A252489 Index of the largest prime which divides n*(n+1).

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

[1, 2, 2, 3, 3, 4, 4, 2, 3, 5, 5, 6, 6, 4, 3, 7, 7, 8, 8, 4, 5, 9, 9, 3, 6, 6, 4, 10, 10, 11, 11, 5, 7, 7, 4, 12, 12, 8, 6, 13, 13, 14, 14, 5, 9, 15, 15, 4, 4, 7, 7, 16, 16, 5, 5, 8, 10, 17, 17, 18, 18, 11, 4, 6, 6, 19, 19, 9, 9, 20, 20, 21, 21, 12, 8, 8, 6]

cp's OEIS Frontend

A252489 Index of the largest prime which divides n*(n+1).

Table of values

List of values

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

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

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