A343891 - cp's OEIS frontend

A343891 List of primitive triples (a, b, c) for integer-sided triangles where side a is the harmonic mean of the 2 other sides b and c, i.e., 2/a = 1/b + 1/c with b < a < c.

n	a(n)
1	4
2	3
3	6
4	12
5	10
6	15
7	15
8	12
9	20
10	21
11	15
12	35
13	24
14	21
15	28
16	35
17	30
18	42
19	40
20	36
21	45
22	45
23	35
24	63
25	55
26	40
27	88
28	56
29	44
30	77
31	60
32	55
33	66
34	63
35	56
36	72
37	72
38	52
39	117
40	77
41	63
42	99
43	80
44	65
45	104
46	84
47	78
48	91
49	91
50	70
51	130
52	99
53	90
54	110
55	105
56	77
57	165
58	112
59	105
60	120
61	117
62	99
63	143
64	120
65	85
66	204
67	132
68	102
69	187

[4, 3, 6, 12, 10, 15, 15, 12, 20, 21, 15, 35, 24, 21, 28, 35, 30, 42, 40, 36, 45, 45, 35, 63, 55, 40, 88, 56, 44, 77, 60, 55, 66, 63, 56, 72, 72, 52, 117, 77, 63, 99, 80, 65, 104, 84, 78, 91, 91, 70, 130, 99, 90, 110, 105, 77, 165, 112, 105, 120, 117, 99, 143, 120, 85, 204, 132, 102, 187]

cp's OEIS Frontend

A343891 List of primitive triples (a, b, c) for integer-sided triangles where side a is the harmonic mean of the 2 other sides b and c, i.e., 2/a = 1/b + 1/c with b < a < c.

Table of values

List of values

n	a(n)
1	4
2	3
3	6
4	12
5	10
6	15
7	15
8	12
9	20
10	21
11	15
12	35
13	24
14	21
15	28
16	35
17	30
18	42
19	40
20	36
21	45
22	45
23	35
24	63
25	55
26	40
27	88
28	56
29	44
30	77
31	60
32	55
33	66
34	63
35	56
36	72
37	72
38	52
39	117
40	77
41	63
42	99
43	80
44	65
45	104
46	84
47	78
48	91
49	91
50	70
51	130
52	99
53	90
54	110
55	105
56	77
57	165
58	112
59	105
60	120
61	117
62	99
63	143
64	120
65	85
66	204
67	132
68	102
69	187

n	a(n)
1	4
2	3
3	6
4	12
5	10
6	15
7	15
8	12
9	20
10	21
11	15
12	35
13	24
14	21
15	28
16	35
17	30
18	42
19	40
20	36
21	45
22	45
23	35
24	63
25	55
26	40
27	88
28	56
29	44
30	77
31	60
32	55
33	66
34	63
35	56
36	72
37	72
38	52
39	117
40	77
41	63
42	99
43	80
44	65
45	104
46	84
47	78
48	91
49	91
50	70
51	130
52	99
53	90
54	110
55	105
56	77
57	165
58	112
59	105
60	120
61	117
62	99
63	143
64	120
65	85
66	204
67	132
68	102
69	187

n	a(n)
1	4
2	3
3	6
4	12
5	10
6	15
7	15
8	12
9	20
10	21
11	15
12	35
13	24
14	21
15	28
16	35
17	30
18	42
19	40
20	36
21	45
22	45
23	35
24	63
25	55
26	40
27	88
28	56
29	44
30	77
31	60
32	55
33	66
34	63
35	56
36	72
37	72
38	52
39	117
40	77
41	63
42	99
43	80
44	65
45	104
46	84
47	78
48	91
49	91
50	70
51	130
52	99
53	90
54	110
55	105
56	77
57	165
58	112
59	105
60	120
61	117
62	99
63	143
64	120
65	85
66	204
67	132
68	102
69	187