A213609 - cp's OEIS frontend

A213609 Smallest number k such that the number of distinct prime divisors of binomial(2k,k) equals n, otherwise 0.

n	a(n)
1	1
2	2
3	4
4	6
5	8
6	11
7	15
8	16
9	18
10	20
11	0
12	28
13	29
14	33
15	38
16	42
17	45
18	48
19	53
20	54
21	60
22	64
23	66
24	67
25	75
26	77
27	80
28	86
29	91
30	92
31	100
32	102
33	104
34	109
35	111
36	110
37	127
38	0
39	128
40	133
41	140
42	144
43	151
44	154
45	153
46	160
47	165
48	170
49	171
50	178
51	0
52	189
53	190
54	192
55	198
56	202
57	209
58	210
59	220
60	225

[1, 2, 4, 6, 8, 11, 15, 16, 18, 20, 0, 28, 29, 33, 38, 42, 45, 48, 53, 54, 60, 64, 66, 67, 75, 77, 80, 86, 91, 92, 100, 102, 104, 109, 111, 110, 127, 0, 128, 133, 140, 144, 151, 154, 153, 160, 165, 170, 171, 178, 0, 189, 190, 192, 198, 202, 209, 210, 220, 225]

cp's OEIS Frontend

A213609 Smallest number k such that the number of distinct prime divisors of binomial(2k,k) equals n, otherwise 0.

Table of values

List of values

n	a(n)
1	1
2	2
3	4
4	6
5	8
6	11
7	15
8	16
9	18
10	20
11	0
12	28
13	29
14	33
15	38
16	42
17	45
18	48
19	53
20	54
21	60
22	64
23	66
24	67
25	75
26	77
27	80
28	86
29	91
30	92
31	100
32	102
33	104
34	109
35	111
36	110
37	127
38	0
39	128
40	133
41	140
42	144
43	151
44	154
45	153
46	160
47	165
48	170
49	171
50	178
51	0
52	189
53	190
54	192
55	198
56	202
57	209
58	210
59	220
60	225

n	a(n)
1	1
2	2
3	4
4	6
5	8
6	11
7	15
8	16
9	18
10	20
11	0
12	28
13	29
14	33
15	38
16	42
17	45
18	48
19	53
20	54
21	60
22	64
23	66
24	67
25	75
26	77
27	80
28	86
29	91
30	92
31	100
32	102
33	104
34	109
35	111
36	110
37	127
38	0
39	128
40	133
41	140
42	144
43	151
44	154
45	153
46	160
47	165
48	170
49	171
50	178
51	0
52	189
53	190
54	192
55	198
56	202
57	209
58	210
59	220
60	225

n	a(n)
1	1
2	2
3	4
4	6
5	8
6	11
7	15
8	16
9	18
10	20
11	0
12	28
13	29
14	33
15	38
16	42
17	45
18	48
19	53
20	54
21	60
22	64
23	66
24	67
25	75
26	77
27	80
28	86
29	91
30	92
31	100
32	102
33	104
34	109
35	111
36	110
37	127
38	0
39	128
40	133
41	140
42	144
43	151
44	154
45	153
46	160
47	165
48	170
49	171
50	178
51	0
52	189
53	190
54	192
55	198
56	202
57	209
58	210
59	220
60	225