A090461 - cp's OEIS frontend

A090461 Numbers k for which there exists a permutation of the numbers 1 to k such that the sum of adjacent numbers is a square.

n	a(n)
1	15
2	16
3	17
4	23
5	25
6	26
7	27
8	28
9	29
10	30
11	31
12	32
13	33
14	34
15	35
16	36
17	37
18	38
19	39
20	40
21	41
22	42
23	43
24	44
25	45
26	46
27	47
28	48
29	49
30	50
31	51
32	52
33	53
34	54
35	55
36	56
37	57
38	58
39	59
40	60
41	61
42	62
43	63
44	64
45	65
46	66
47	67
48	68
49	69
50	70
51	71
52	72
53	73
54	74
55	75
56	76
57	77
58	78
59	79
60	80
61	81
62	82
63	83
64	84
65	85
66	86
67	87
68	88
69	89

[15, 16, 17, 23, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89]

cp's OEIS Frontend

A090461 Numbers k for which there exists a permutation of the numbers 1 to k such that the sum of adjacent numbers is a square.

Table of values

List of values

n	a(n)
1	15
2	16
3	17
4	23
5	25
6	26
7	27
8	28
9	29
10	30
11	31
12	32
13	33
14	34
15	35
16	36
17	37
18	38
19	39
20	40
21	41
22	42
23	43
24	44
25	45
26	46
27	47
28	48
29	49
30	50
31	51
32	52
33	53
34	54
35	55
36	56
37	57
38	58
39	59
40	60
41	61
42	62
43	63
44	64
45	65
46	66
47	67
48	68
49	69
50	70
51	71
52	72
53	73
54	74
55	75
56	76
57	77
58	78
59	79
60	80
61	81
62	82
63	83
64	84
65	85
66	86
67	87
68	88
69	89

n	a(n)
1	15
2	16
3	17
4	23
5	25
6	26
7	27
8	28
9	29
10	30
11	31
12	32
13	33
14	34
15	35
16	36
17	37
18	38
19	39
20	40
21	41
22	42
23	43
24	44
25	45
26	46
27	47
28	48
29	49
30	50
31	51
32	52
33	53
34	54
35	55
36	56
37	57
38	58
39	59
40	60
41	61
42	62
43	63
44	64
45	65
46	66
47	67
48	68
49	69
50	70
51	71
52	72
53	73
54	74
55	75
56	76
57	77
58	78
59	79
60	80
61	81
62	82
63	83
64	84
65	85
66	86
67	87
68	88
69	89

n	a(n)
1	15
2	16
3	17
4	23
5	25
6	26
7	27
8	28
9	29
10	30
11	31
12	32
13	33
14	34
15	35
16	36
17	37
18	38
19	39
20	40
21	41
22	42
23	43
24	44
25	45
26	46
27	47
28	48
29	49
30	50
31	51
32	52
33	53
34	54
35	55
36	56
37	57
38	58
39	59
40	60
41	61
42	62
43	63
44	64
45	65
46	66
47	67
48	68
49	69
50	70
51	71
52	72
53	73
54	74
55	75
56	76
57	77
58	78
59	79
60	80
61	81
62	82
63	83
64	84
65	85
66	86
67	87
68	88
69	89