A020921 - cp's OEIS frontend

A020921 Triangle read by rows: T(m,n) = number of solutions to 1 <= a(1) < a(2) < ... < a(m) <= n, where gcd( a(1), a(2), ..., a(m), n) = 1.

n	a(n)
0	1
1	1
2	1
3	0
4	1
5	1
6	0
7	2
8	3
9	1
10	0
11	2
12	5
13	4
14	1
15	0
16	4
17	10
18	10
19	5
20	1
21	0
22	2
23	11
24	19
25	15
26	6
27	1
28	0
29	6
30	21
31	35
32	35
33	21
34	7
35	1
36	0
37	4
38	22
39	52
40	69
41	56
42	28
43	8
44	1
45	0
46	6
47	33
48	83
49	126
50	126
51	84
52	36
53	9
54	1
55	0
56	4
57	34
58	110
59	205
60	251
61	210
62	120
63	45
64	10
65	1
66	0
67	10
68	55
69	165
70	330
71	462
72	462
73	330
74	165
75	55
76	11

[1, 1, 1, 0, 1, 1, 0, 2, 3, 1, 0, 2, 5, 4, 1, 0, 4, 10, 10, 5, 1, 0, 2, 11, 19, 15, 6, 1, 0, 6, 21, 35, 35, 21, 7, 1, 0, 4, 22, 52, 69, 56, 28, 8, 1, 0, 6, 33, 83, 126, 126, 84, 36, 9, 1, 0, 4, 34, 110, 205, 251, 210, 120, 45, 10, 1, 0, 10, 55, 165, 330, 462, 462, 330, 165, 55, 11]

cp's OEIS Frontend

A020921 Triangle read by rows: T(m,n) = number of solutions to 1 <= a(1) < a(2) < ... < a(m) <= n, where gcd( a(1), a(2), ..., a(m), n) = 1.

Table of values

List of values

n	a(n)
0	1
1	1
2	1
3	0
4	1
5	1
6	0
7	2
8	3
9	1
10	0
11	2
12	5
13	4
14	1
15	0
16	4
17	10
18	10
19	5
20	1
21	0
22	2
23	11
24	19
25	15
26	6
27	1
28	0
29	6
30	21
31	35
32	35
33	21
34	7
35	1
36	0
37	4
38	22
39	52
40	69
41	56
42	28
43	8
44	1
45	0
46	6
47	33
48	83
49	126
50	126
51	84
52	36
53	9
54	1
55	0
56	4
57	34
58	110
59	205
60	251
61	210
62	120
63	45
64	10
65	1
66	0
67	10
68	55
69	165
70	330
71	462
72	462
73	330
74	165
75	55
76	11

n	a(n)
0	1
1	1
2	1
3	0
4	1
5	1
6	0
7	2
8	3
9	1
10	0
11	2
12	5
13	4
14	1
15	0
16	4
17	10
18	10
19	5
20	1
21	0
22	2
23	11
24	19
25	15
26	6
27	1
28	0
29	6
30	21
31	35
32	35
33	21
34	7
35	1
36	0
37	4
38	22
39	52
40	69
41	56
42	28
43	8
44	1
45	0
46	6
47	33
48	83
49	126
50	126
51	84
52	36
53	9
54	1
55	0
56	4
57	34
58	110
59	205
60	251
61	210
62	120
63	45
64	10
65	1
66	0
67	10
68	55
69	165
70	330
71	462
72	462
73	330
74	165
75	55
76	11

n	a(n)
0	1
1	1
2	1
3	0
4	1
5	1
6	0
7	2
8	3
9	1
10	0
11	2
12	5
13	4
14	1
15	0
16	4
17	10
18	10
19	5
20	1
21	0
22	2
23	11
24	19
25	15
26	6
27	1
28	0
29	6
30	21
31	35
32	35
33	21
34	7
35	1
36	0
37	4
38	22
39	52
40	69
41	56
42	28
43	8
44	1
45	0
46	6
47	33
48	83
49	126
50	126
51	84
52	36
53	9
54	1
55	0
56	4
57	34
58	110
59	205
60	251
61	210
62	120
63	45
64	10
65	1
66	0
67	10
68	55
69	165
70	330
71	462
72	462
73	330
74	165
75	55
76	11