A249167 - cp's OEIS frontend

A249167 a(n) = n if n <= 3, otherwise the smallest number not occurring earlier having at least one common Fermi-Dirac factor with a(n-2), but none with a(n-1).

n	a(n)
1	1
2	2
3	3
4	8
5	15
6	4
7	5
8	12
9	10
10	21
11	18
12	7
13	6
14	28
15	22
16	20
17	11
18	24
19	55
20	14
21	33
22	26
23	27
24	13
25	9
26	39
27	36
28	30
29	44
30	32
31	52
32	16
33	40
34	48
35	34
36	57
37	17
38	19
39	51
40	38
41	60
42	46
43	35
44	23
45	42
46	92
47	50
48	64
49	25
50	56
51	75
52	58
53	69
54	29
55	54
56	116
57	45
58	68
59	63
60	76
61	70
62	100
63	62
64	84
65	31
66	66
67	124
68	74
69	93
70	37
71	78
72	148
73	65
74	72
75	80

[1, 2, 3, 8, 15, 4, 5, 12, 10, 21, 18, 7, 6, 28, 22, 20, 11, 24, 55, 14, 33, 26, 27, 13, 9, 39, 36, 30, 44, 32, 52, 16, 40, 48, 34, 57, 17, 19, 51, 38, 60, 46, 35, 23, 42, 92, 50, 64, 25, 56, 75, 58, 69, 29, 54, 116, 45, 68, 63, 76, 70, 100, 62, 84, 31, 66, 124, 74, 93, 37, 78, 148, 65, 72, 80]

cp's OEIS Frontend

A249167 a(n) = n if n <= 3, otherwise the smallest number not occurring earlier having at least one common Fermi-Dirac factor with a(n-2), but none with a(n-1).

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	8
5	15
6	4
7	5
8	12
9	10
10	21
11	18
12	7
13	6
14	28
15	22
16	20
17	11
18	24
19	55
20	14
21	33
22	26
23	27
24	13
25	9
26	39
27	36
28	30
29	44
30	32
31	52
32	16
33	40
34	48
35	34
36	57
37	17
38	19
39	51
40	38
41	60
42	46
43	35
44	23
45	42
46	92
47	50
48	64
49	25
50	56
51	75
52	58
53	69
54	29
55	54
56	116
57	45
58	68
59	63
60	76
61	70
62	100
63	62
64	84
65	31
66	66
67	124
68	74
69	93
70	37
71	78
72	148
73	65
74	72
75	80

n	a(n)
1	1
2	2
3	3
4	8
5	15
6	4
7	5
8	12
9	10
10	21
11	18
12	7
13	6
14	28
15	22
16	20
17	11
18	24
19	55
20	14
21	33
22	26
23	27
24	13
25	9
26	39
27	36
28	30
29	44
30	32
31	52
32	16
33	40
34	48
35	34
36	57
37	17
38	19
39	51
40	38
41	60
42	46
43	35
44	23
45	42
46	92
47	50
48	64
49	25
50	56
51	75
52	58
53	69
54	29
55	54
56	116
57	45
58	68
59	63
60	76
61	70
62	100
63	62
64	84
65	31
66	66
67	124
68	74
69	93
70	37
71	78
72	148
73	65
74	72
75	80

n	a(n)
1	1
2	2
3	3
4	8
5	15
6	4
7	5
8	12
9	10
10	21
11	18
12	7
13	6
14	28
15	22
16	20
17	11
18	24
19	55
20	14
21	33
22	26
23	27
24	13
25	9
26	39
27	36
28	30
29	44
30	32
31	52
32	16
33	40
34	48
35	34
36	57
37	17
38	19
39	51
40	38
41	60
42	46
43	35
44	23
45	42
46	92
47	50
48	64
49	25
50	56
51	75
52	58
53	69
54	29
55	54
56	116
57	45
58	68
59	63
60	76
61	70
62	100
63	62
64	84
65	31
66	66
67	124
68	74
69	93
70	37
71	78
72	148
73	65
74	72
75	80