A248123 - cp's OEIS frontend

A248123 Least integer m > 0 such that gcd(m,n) = 1 and m*n | C(m+n), where C(k) refers to the k-th Catalan number binomial(2k,k)/(k+1).

n	a(n)
1	1
2	3
3	2
4	21
5	9
6	11
7	11
8	77
9	5
10	13
11	6
12	85
13	10
14	5
15	1
16	77
17	11
18	5
19	11
20	1
21	4
22	7
23	13
24	29
25	18
26	7
27	14
28	1
29	15
30	11
31	17
32	189
33	19
34	9
35	6
36	5
37	23
38	15
39	7
40	49
41	23
42	1
43	22
44	17
45	1
46	13
47	25
48	13
49	26
50	19
51	11
52	9
53	28
54	71
55	18
56	29
57	10
58	15
59	31
60	13
61	34
62	17
63	5
64	381
65	9
66	1
67	35
68	9
69	19
70	9

[1, 3, 2, 21, 9, 11, 11, 77, 5, 13, 6, 85, 10, 5, 1, 77, 11, 5, 11, 1, 4, 7, 13, 29, 18, 7, 14, 1, 15, 11, 17, 189, 19, 9, 6, 5, 23, 15, 7, 49, 23, 1, 22, 17, 1, 13, 25, 13, 26, 19, 11, 9, 28, 71, 18, 29, 10, 15, 31, 13, 34, 17, 5, 381, 9, 1, 35, 9, 19, 9]

cp's OEIS Frontend

A248123 Least integer m > 0 such that gcd(m,n) = 1 and m*n | C(m+n), where C(k) refers to the k-th Catalan number binomial(2k,k)/(k+1).

Table of values

List of values

n	a(n)
1	1
2	3
3	2
4	21
5	9
6	11
7	11
8	77
9	5
10	13
11	6
12	85
13	10
14	5
15	1
16	77
17	11
18	5
19	11
20	1
21	4
22	7
23	13
24	29
25	18
26	7
27	14
28	1
29	15
30	11
31	17
32	189
33	19
34	9
35	6
36	5
37	23
38	15
39	7
40	49
41	23
42	1
43	22
44	17
45	1
46	13
47	25
48	13
49	26
50	19
51	11
52	9
53	28
54	71
55	18
56	29
57	10
58	15
59	31
60	13
61	34
62	17
63	5
64	381
65	9
66	1
67	35
68	9
69	19
70	9

n	a(n)
1	1
2	3
3	2
4	21
5	9
6	11
7	11
8	77
9	5
10	13
11	6
12	85
13	10
14	5
15	1
16	77
17	11
18	5
19	11
20	1
21	4
22	7
23	13
24	29
25	18
26	7
27	14
28	1
29	15
30	11
31	17
32	189
33	19
34	9
35	6
36	5
37	23
38	15
39	7
40	49
41	23
42	1
43	22
44	17
45	1
46	13
47	25
48	13
49	26
50	19
51	11
52	9
53	28
54	71
55	18
56	29
57	10
58	15
59	31
60	13
61	34
62	17
63	5
64	381
65	9
66	1
67	35
68	9
69	19
70	9

n	a(n)
1	1
2	3
3	2
4	21
5	9
6	11
7	11
8	77
9	5
10	13
11	6
12	85
13	10
14	5
15	1
16	77
17	11
18	5
19	11
20	1
21	4
22	7
23	13
24	29
25	18
26	7
27	14
28	1
29	15
30	11
31	17
32	189
33	19
34	9
35	6
36	5
37	23
38	15
39	7
40	49
41	23
42	1
43	22
44	17
45	1
46	13
47	25
48	13
49	26
50	19
51	11
52	9
53	28
54	71
55	18
56	29
57	10
58	15
59	31
60	13
61	34
62	17
63	5
64	381
65	9
66	1
67	35
68	9
69	19
70	9