A355482 - cp's OEIS frontend

A355482 a(1) = 2; for n > 1, a(n) is the smallest positive number that has not yet appeared such that the number of 1-bits in the binary expansion of a(n) equals the number of proper divisors of a(n-1).

n	a(n)
1	2
2	4
3	3
4	8
5	7
6	16
7	15
8	11
9	32
10	31
11	64
12	63
13	47
14	128
15	127
16	256
17	255
18	191
19	512
20	511
21	13
22	1024
23	1023
24	223
25	2048
26	2047
27	14
28	19
29	4096
30	4095
31	8388607
32	21
33	22
34	25
35	5
36	8192
37	8191
38	16384
39	16383
40	239
41	32768
42	32767
43	247
44	26
45	28
46	55
47	35
48	37
49	65536
50	65535
51	49151
52	38
53	41
54	131072
55	131071
56	262144
57	262143

[2, 4, 3, 8, 7, 16, 15, 11, 32, 31, 64, 63, 47, 128, 127, 256, 255, 191, 512, 511, 13, 1024, 1023, 223, 2048, 2047, 14, 19, 4096, 4095, 8388607, 21, 22, 25, 5, 8192, 8191, 16384, 16383, 239, 32768, 32767, 247, 26, 28, 55, 35, 37, 65536, 65535, 49151, 38, 41, 131072, 131071, 262144, 262143]

cp's OEIS Frontend

A355482 a(1) = 2; for n > 1, a(n) is the smallest positive number that has not yet appeared such that the number of 1-bits in the binary expansion of a(n) equals the number of proper divisors of a(n-1).

Table of values

List of values