A261345 - cp's OEIS frontend

A261345 Number of distinct prime divisors among the numbers k^2 + 1 for k in 1 <= k <= n.

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

[1, 2, 2, 3, 4, 5, 5, 5, 6, 7, 8, 9, 9, 10, 11, 12, 12, 12, 13, 14, 14, 15, 16, 17, 18, 19, 20, 21, 22, 22, 22, 22, 23, 24, 25, 26, 27, 27, 28, 29, 29, 30, 30, 31, 32, 32, 32, 33, 34, 34, 35, 36, 37, 38, 38, 39, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 49, 50]

cp's OEIS Frontend

A261345 Number of distinct prime divisors among the numbers k^2 + 1 for k in 1 <= k <= n.

Table of values

List of values

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

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

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