A221918 - cp's OEIS frontend

A221918 Triangle of denominators of sum of two unit fractions: 1/n + 1/m, n >= m >= 1.

n	a(n)
1	1
2	2
3	1
4	3
5	6
6	3
7	4
8	4
9	12
10	2
11	5
12	10
13	15
14	20
15	5
16	6
17	3
18	2
19	12
20	30
21	3
22	7
23	14
24	21
25	28
26	35
27	42
28	7
29	8
30	8
31	24
32	8
33	40
34	24
35	56
36	4
37	9
38	18
39	9
40	36
41	45
42	18
43	63
44	72
45	9
46	10
47	5
48	30
49	20
50	10
51	15
52	70
53	40
54	90
55	5
56	11
57	22
58	33
59	44
60	55
61	66
62	77
63	88
64	99
65	110
66	11
67	12
68	12
69	12
70	3
71	60
72	4
73	84
74	24
75	36
76	60
77	132
78	6

[1, 2, 1, 3, 6, 3, 4, 4, 12, 2, 5, 10, 15, 20, 5, 6, 3, 2, 12, 30, 3, 7, 14, 21, 28, 35, 42, 7, 8, 8, 24, 8, 40, 24, 56, 4, 9, 18, 9, 36, 45, 18, 63, 72, 9, 10, 5, 30, 20, 10, 15, 70, 40, 90, 5, 11, 22, 33, 44, 55, 66, 77, 88, 99, 110, 11, 12, 12, 12, 3, 60, 4, 84, 24, 36, 60, 132, 6]

cp's OEIS Frontend

A221918 Triangle of denominators of sum of two unit fractions: 1/n + 1/m, n >= m >= 1.

Table of values

List of values

n	a(n)
1	1
2	2
3	1
4	3
5	6
6	3
7	4
8	4
9	12
10	2
11	5
12	10
13	15
14	20
15	5
16	6
17	3
18	2
19	12
20	30
21	3
22	7
23	14
24	21
25	28
26	35
27	42
28	7
29	8
30	8
31	24
32	8
33	40
34	24
35	56
36	4
37	9
38	18
39	9
40	36
41	45
42	18
43	63
44	72
45	9
46	10
47	5
48	30
49	20
50	10
51	15
52	70
53	40
54	90
55	5
56	11
57	22
58	33
59	44
60	55
61	66
62	77
63	88
64	99
65	110
66	11
67	12
68	12
69	12
70	3
71	60
72	4
73	84
74	24
75	36
76	60
77	132
78	6

n	a(n)
1	1
2	2
3	1
4	3
5	6
6	3
7	4
8	4
9	12
10	2
11	5
12	10
13	15
14	20
15	5
16	6
17	3
18	2
19	12
20	30
21	3
22	7
23	14
24	21
25	28
26	35
27	42
28	7
29	8
30	8
31	24
32	8
33	40
34	24
35	56
36	4
37	9
38	18
39	9
40	36
41	45
42	18
43	63
44	72
45	9
46	10
47	5
48	30
49	20
50	10
51	15
52	70
53	40
54	90
55	5
56	11
57	22
58	33
59	44
60	55
61	66
62	77
63	88
64	99
65	110
66	11
67	12
68	12
69	12
70	3
71	60
72	4
73	84
74	24
75	36
76	60
77	132
78	6

n	a(n)
1	1
2	2
3	1
4	3
5	6
6	3
7	4
8	4
9	12
10	2
11	5
12	10
13	15
14	20
15	5
16	6
17	3
18	2
19	12
20	30
21	3
22	7
23	14
24	21
25	28
26	35
27	42
28	7
29	8
30	8
31	24
32	8
33	40
34	24
35	56
36	4
37	9
38	18
39	9
40	36
41	45
42	18
43	63
44	72
45	9
46	10
47	5
48	30
49	20
50	10
51	15
52	70
53	40
54	90
55	5
56	11
57	22
58	33
59	44
60	55
61	66
62	77
63	88
64	99
65	110
66	11
67	12
68	12
69	12
70	3
71	60
72	4
73	84
74	24
75	36
76	60
77	132
78	6