A123031 - cp's OEIS frontend

A123031 Array read by antidiagonals: row i (i>=0) contains those positive integers n >= 2 for which the multiset { n mod k : k=2,3,...,n } contains exactly one copy of i.

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

[2, 3, 3, 5, 4, 5, 7, 6, 6, 7, 9, 8, 7, 8, 11, 11, 10, 9, 9, 12, 13, 13, 12, 11, 10, 13, 14, 17, 15, 14, 13, 12, 12, 15, 18, 19, 17, 16, 15, 14, 13, 14, 19, 20, 23, 19, 18, 17, 16, 15, 15, 16, 21, 24, 29, 21, 20, 19, 18, 17, 16, 17, 20, 25, 30, 31, 23, 22, 21, 20, 19, 18, 18, 21, 22]

cp's OEIS Frontend

A123031 Array read by antidiagonals: row i (i>=0) contains those positive integers n >= 2 for which the multiset { n mod k : k=2,3,...,n } contains exactly one copy of i.

Table of values

List of values

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

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

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