A275708 - cp's OEIS frontend

A275708 a(1)=1, a(2)=2; thereafter a(n) is the smallest positive integer not yet used such that a(n)+a(n-1)-a(n-2) is a square.

n	a(n)
1	1
2	2
3	3
4	8
5	4
6	5
7	15
8	6
9	10
10	12
11	7
12	9
13	14
14	11
15	19
16	17
17	18
18	24
19	30
20	43
21	23
22	21
23	27
24	58
25	33
26	26
27	16
28	35
29	45
30	39
31	22
32	42
33	29
34	38
35	40
36	34
37	31
38	28
39	52
40	25
41	36
42	53
43	32
44	37
45	20
46	66
47	54
48	13
49	50
50	44
51	55
52	70
53	49
54	46
55	67

[1, 2, 3, 8, 4, 5, 15, 6, 10, 12, 7, 9, 14, 11, 19, 17, 18, 24, 30, 43, 23, 21, 27, 58, 33, 26, 16, 35, 45, 39, 22, 42, 29, 38, 40, 34, 31, 28, 52, 25, 36, 53, 32, 37, 20, 66, 54, 13, 50, 44, 55, 70, 49, 46, 67]

cp's OEIS Frontend

A275708 a(1)=1, a(2)=2; thereafter a(n) is the smallest positive integer not yet used such that a(n)+a(n-1)-a(n-2) is a square.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	8
5	4
6	5
7	15
8	6
9	10
10	12
11	7
12	9
13	14
14	11
15	19
16	17
17	18
18	24
19	30
20	43
21	23
22	21
23	27
24	58
25	33
26	26
27	16
28	35
29	45
30	39
31	22
32	42
33	29
34	38
35	40
36	34
37	31
38	28
39	52
40	25
41	36
42	53
43	32
44	37
45	20
46	66
47	54
48	13
49	50
50	44
51	55
52	70
53	49
54	46
55	67

n	a(n)
1	1
2	2
3	3
4	8
5	4
6	5
7	15
8	6
9	10
10	12
11	7
12	9
13	14
14	11
15	19
16	17
17	18
18	24
19	30
20	43
21	23
22	21
23	27
24	58
25	33
26	26
27	16
28	35
29	45
30	39
31	22
32	42
33	29
34	38
35	40
36	34
37	31
38	28
39	52
40	25
41	36
42	53
43	32
44	37
45	20
46	66
47	54
48	13
49	50
50	44
51	55
52	70
53	49
54	46
55	67

n	a(n)
1	1
2	2
3	3
4	8
5	4
6	5
7	15
8	6
9	10
10	12
11	7
12	9
13	14
14	11
15	19
16	17
17	18
18	24
19	30
20	43
21	23
22	21
23	27
24	58
25	33
26	26
27	16
28	35
29	45
30	39
31	22
32	42
33	29
34	38
35	40
36	34
37	31
38	28
39	52
40	25
41	36
42	53
43	32
44	37
45	20
46	66
47	54
48	13
49	50
50	44
51	55
52	70
53	49
54	46
55	67