A375829 - cp's OEIS frontend

A375829 a(1) = 1; for n > 1, a(n) is the smallest unused positive number such that (a(n-1) AND a(n)) = 0 if a(n-1) is prime, otherwise (a(n-1) AND a(n)) = a(n-1), where AND is the binary AND operation.

n	a(n)
1	1
2	3
3	4
4	5
5	2
6	8
7	9
8	11
9	16
10	17
11	6
12	7
13	24
14	25
15	27
16	31
17	32
18	33
19	35
20	39
21	47
22	64
23	65
24	67
25	12
26	13
27	18
28	19
29	36
30	37
31	10
32	14
33	15
34	63
35	127
36	128
37	129
38	131
39	20
40	21
41	23
42	40
43	41
44	22
45	30
46	62
47	126
48	254
49	255
50	511
51	1023
52	2047
53	4095
54	8191
55	8192
56	8193
57	8195
58	8199
59	8207
60	8223
61	8255
62	8319
63	8447
64	256
65	257
66	26
67	58
68	59
69	68
70	69
71	71
72	48
73	49
74	51
75	55
76	119
77	247
78	503
79	512
80	513
81	515
82	519

[1, 3, 4, 5, 2, 8, 9, 11, 16, 17, 6, 7, 24, 25, 27, 31, 32, 33, 35, 39, 47, 64, 65, 67, 12, 13, 18, 19, 36, 37, 10, 14, 15, 63, 127, 128, 129, 131, 20, 21, 23, 40, 41, 22, 30, 62, 126, 254, 255, 511, 1023, 2047, 4095, 8191, 8192, 8193, 8195, 8199, 8207, 8223, 8255, 8319, 8447, 256, 257, 26, 58, 59, 68, 69, 71, 48, 49, 51, 55, 119, 247, 503, 512, 513, 515, 519]

cp's OEIS Frontend

A375829 a(1) = 1; for n > 1, a(n) is the smallest unused positive number such that (a(n-1) AND a(n)) = 0 if a(n-1) is prime, otherwise (a(n-1) AND a(n)) = a(n-1), where AND is the binary AND operation.

Table of values

List of values