A308085 - cp's OEIS frontend

A308085 a(n) is the least positive number k such that n(n-1)/2 + k(k-1)/2 is a square.

n	a(n)
1	1
2	1
3	2
4	3
5	4
6	2
7	6
8	7
9	1
10	9
11	10
12	6
13	3
14	13
15	14
16	2
17	16
18	17
19	18
20	4
21	6
22	21
23	3
24	23
25	24
26	9
27	5
28	27
29	13
30	4
31	30
32	31
33	2
34	6
35	34
36	35
37	5
38	37
39	38
40	16
41	7
42	30
43	23
44	6
45	44
46	20
47	46
48	8
49	16
50	1
51	7
52	51
53	12
54	53
55	9
56	42
57	23
58	8
59	58
60	59
61	60
62	10
63	27
64	63
65	9
66	65
67	20
68	67
69	11
70	69
71	6
72	10
73	72
74	3
75	44
76	12
77	21
78	77
79	11
80	34
81	80
82	46

[1, 1, 2, 3, 4, 2, 6, 7, 1, 9, 10, 6, 3, 13, 14, 2, 16, 17, 18, 4, 6, 21, 3, 23, 24, 9, 5, 27, 13, 4, 30, 31, 2, 6, 34, 35, 5, 37, 38, 16, 7, 30, 23, 6, 44, 20, 46, 8, 16, 1, 7, 51, 12, 53, 9, 42, 23, 8, 58, 59, 60, 10, 27, 63, 9, 65, 20, 67, 11, 69, 6, 10, 72, 3, 44, 12, 21, 77, 11, 34, 80, 46]

cp's OEIS Frontend

A308085 a(n) is the least positive number k such that n(n-1)/2 + k(k-1)/2 is a square.

Table of values

List of values

n	a(n)
1	1
2	1
3	2
4	3
5	4
6	2
7	6
8	7
9	1
10	9
11	10
12	6
13	3
14	13
15	14
16	2
17	16
18	17
19	18
20	4
21	6
22	21
23	3
24	23
25	24
26	9
27	5
28	27
29	13
30	4
31	30
32	31
33	2
34	6
35	34
36	35
37	5
38	37
39	38
40	16
41	7
42	30
43	23
44	6
45	44
46	20
47	46
48	8
49	16
50	1
51	7
52	51
53	12
54	53
55	9
56	42
57	23
58	8
59	58
60	59
61	60
62	10
63	27
64	63
65	9
66	65
67	20
68	67
69	11
70	69
71	6
72	10
73	72
74	3
75	44
76	12
77	21
78	77
79	11
80	34
81	80
82	46

n	a(n)
1	1
2	1
3	2
4	3
5	4
6	2
7	6
8	7
9	1
10	9
11	10
12	6
13	3
14	13
15	14
16	2
17	16
18	17
19	18
20	4
21	6
22	21
23	3
24	23
25	24
26	9
27	5
28	27
29	13
30	4
31	30
32	31
33	2
34	6
35	34
36	35
37	5
38	37
39	38
40	16
41	7
42	30
43	23
44	6
45	44
46	20
47	46
48	8
49	16
50	1
51	7
52	51
53	12
54	53
55	9
56	42
57	23
58	8
59	58
60	59
61	60
62	10
63	27
64	63
65	9
66	65
67	20
68	67
69	11
70	69
71	6
72	10
73	72
74	3
75	44
76	12
77	21
78	77
79	11
80	34
81	80
82	46

cp's OEIS Frontend

A308085 a(n) is the least positive number k such that n*(n-1)/2 + k*(k-1)/2 is a square.

Table of values

List of values

A308085 a(n) is the least positive number k such that n(n-1)/2 + k(k-1)/2 is a square.

n	a(n)
1	1
2	1
3	2
4	3
5	4
6	2
7	6
8	7
9	1
10	9
11	10
12	6
13	3
14	13
15	14
16	2
17	16
18	17
19	18
20	4
21	6
22	21
23	3
24	23
25	24
26	9
27	5
28	27
29	13
30	4
31	30
32	31
33	2
34	6
35	34
36	35
37	5
38	37
39	38
40	16
41	7
42	30
43	23
44	6
45	44
46	20
47	46
48	8
49	16
50	1
51	7
52	51
53	12
54	53
55	9
56	42
57	23
58	8
59	58
60	59
61	60
62	10
63	27
64	63
65	9
66	65
67	20
68	67
69	11
70	69
71	6
72	10
73	72
74	3
75	44
76	12
77	21
78	77
79	11
80	34
81	80
82	46