A076991 - cp's OEIS frontend

A076991 a(1) = 1, a(2) = 2, a(n) = smallest positive integer not occurring earlier such that the sum of three successive terms is a square.

n	a(n)
1	1
2	2
3	6
4	8
5	11
6	17
7	21
8	26
9	34
10	4
11	43
12	53
13	25
14	3
15	36
16	10
17	18
18	72
19	31
20	41
21	9
22	14
23	13
24	22
25	29
26	30
27	5
28	46
29	49
30	74
31	73
32	78
33	45
34	102
35	109
36	113
37	67
38	16
39	38
40	27
41	35
42	19
43	90
44	12
45	42
46	115
47	39
48	15
49	142
50	68
51	79
52	177
53	33
54	114
55	214
56	156
57	71
58	62
59	63
60	44
61	37
62	40
63	23
64	58
65	88
66	50
67	87
68	7
69	75

[1, 2, 6, 8, 11, 17, 21, 26, 34, 4, 43, 53, 25, 3, 36, 10, 18, 72, 31, 41, 9, 14, 13, 22, 29, 30, 5, 46, 49, 74, 73, 78, 45, 102, 109, 113, 67, 16, 38, 27, 35, 19, 90, 12, 42, 115, 39, 15, 142, 68, 79, 177, 33, 114, 214, 156, 71, 62, 63, 44, 37, 40, 23, 58, 88, 50, 87, 7, 75]

cp's OEIS Frontend

A076991 a(1) = 1, a(2) = 2, a(n) = smallest positive integer not occurring earlier such that the sum of three successive terms is a square.

Table of values

List of values

n	a(n)
1	1
2	2
3	6
4	8
5	11
6	17
7	21
8	26
9	34
10	4
11	43
12	53
13	25
14	3
15	36
16	10
17	18
18	72
19	31
20	41
21	9
22	14
23	13
24	22
25	29
26	30
27	5
28	46
29	49
30	74
31	73
32	78
33	45
34	102
35	109
36	113
37	67
38	16
39	38
40	27
41	35
42	19
43	90
44	12
45	42
46	115
47	39
48	15
49	142
50	68
51	79
52	177
53	33
54	114
55	214
56	156
57	71
58	62
59	63
60	44
61	37
62	40
63	23
64	58
65	88
66	50
67	87
68	7
69	75

n	a(n)
1	1
2	2
3	6
4	8
5	11
6	17
7	21
8	26
9	34
10	4
11	43
12	53
13	25
14	3
15	36
16	10
17	18
18	72
19	31
20	41
21	9
22	14
23	13
24	22
25	29
26	30
27	5
28	46
29	49
30	74
31	73
32	78
33	45
34	102
35	109
36	113
37	67
38	16
39	38
40	27
41	35
42	19
43	90
44	12
45	42
46	115
47	39
48	15
49	142
50	68
51	79
52	177
53	33
54	114
55	214
56	156
57	71
58	62
59	63
60	44
61	37
62	40
63	23
64	58
65	88
66	50
67	87
68	7
69	75

n	a(n)
1	1
2	2
3	6
4	8
5	11
6	17
7	21
8	26
9	34
10	4
11	43
12	53
13	25
14	3
15	36
16	10
17	18
18	72
19	31
20	41
21	9
22	14
23	13
24	22
25	29
26	30
27	5
28	46
29	49
30	74
31	73
32	78
33	45
34	102
35	109
36	113
37	67
38	16
39	38
40	27
41	35
42	19
43	90
44	12
45	42
46	115
47	39
48	15
49	142
50	68
51	79
52	177
53	33
54	114
55	214
56	156
57	71
58	62
59	63
60	44
61	37
62	40
63	23
64	58
65	88
66	50
67	87
68	7
69	75