A330403 - cp's OEIS frontend

A330403 Lexicographically earliest sequence of distinct positive terms with an associate sequence t such that t(0) = 0, and for any n > 0, at least one of t(n-1) - a(n) or t(n-1) + a(n) is a square; in case t(n-1) - a(n) is a square, set t(n) = t(n-1) - a(n), otherwise set t(n) = t(n-1) + a(n).

n	a(n)
1	1
2	3
3	4
4	9
5	5
6	12
7	7
8	8
9	15
10	16
11	25
12	11
13	13
14	24
15	21
16	32
17	20
18	33
19	40
20	27
21	28
22	17
23	19
24	36
25	39
26	56
27	45
28	35
29	48
30	49
31	64
32	55
33	72
34	63
35	23
36	57
37	60
38	77
39	65
40	84
41	44
42	52
43	29
44	31
45	68
46	37
47	80
48	41
49	76
50	99
51	81
52	95
53	51
54	69
55	87
56	105
57	123
58	43
59	88
60	47
61	92
62	141
63	96
64	129
65	111
66	93

[1, 3, 4, 9, 5, 12, 7, 8, 15, 16, 25, 11, 13, 24, 21, 32, 20, 33, 40, 27, 28, 17, 19, 36, 39, 56, 45, 35, 48, 49, 64, 55, 72, 63, 23, 57, 60, 77, 65, 84, 44, 52, 29, 31, 68, 37, 80, 41, 76, 99, 81, 95, 51, 69, 87, 105, 123, 43, 88, 47, 92, 141, 96, 129, 111, 93]

cp's OEIS Frontend

A330403 Lexicographically earliest sequence of distinct positive terms with an associate sequence t such that t(0) = 0, and for any n > 0, at least one of t(n-1) - a(n) or t(n-1) + a(n) is a square; in case t(n-1) - a(n) is a square, set t(n) = t(n-1) - a(n), otherwise set t(n) = t(n-1) + a(n).

Table of values

List of values

n	a(n)
1	1
2	3
3	4
4	9
5	5
6	12
7	7
8	8
9	15
10	16
11	25
12	11
13	13
14	24
15	21
16	32
17	20
18	33
19	40
20	27
21	28
22	17
23	19
24	36
25	39
26	56
27	45
28	35
29	48
30	49
31	64
32	55
33	72
34	63
35	23
36	57
37	60
38	77
39	65
40	84
41	44
42	52
43	29
44	31
45	68
46	37
47	80
48	41
49	76
50	99
51	81
52	95
53	51
54	69
55	87
56	105
57	123
58	43
59	88
60	47
61	92
62	141
63	96
64	129
65	111
66	93

n	a(n)
1	1
2	3
3	4
4	9
5	5
6	12
7	7
8	8
9	15
10	16
11	25
12	11
13	13
14	24
15	21
16	32
17	20
18	33
19	40
20	27
21	28
22	17
23	19
24	36
25	39
26	56
27	45
28	35
29	48
30	49
31	64
32	55
33	72
34	63
35	23
36	57
37	60
38	77
39	65
40	84
41	44
42	52
43	29
44	31
45	68
46	37
47	80
48	41
49	76
50	99
51	81
52	95
53	51
54	69
55	87
56	105
57	123
58	43
59	88
60	47
61	92
62	141
63	96
64	129
65	111
66	93

n	a(n)
1	1
2	3
3	4
4	9
5	5
6	12
7	7
8	8
9	15
10	16
11	25
12	11
13	13
14	24
15	21
16	32
17	20
18	33
19	40
20	27
21	28
22	17
23	19
24	36
25	39
26	56
27	45
28	35
29	48
30	49
31	64
32	55
33	72
34	63
35	23
36	57
37	60
38	77
39	65
40	84
41	44
42	52
43	29
44	31
45	68
46	37
47	80
48	41
49	76
50	99
51	81
52	95
53	51
54	69
55	87
56	105
57	123
58	43
59	88
60	47
61	92
62	141
63	96
64	129
65	111
66	93