A204983 - cp's OEIS frontend

A204983 a(n) = 2^(k-1)-2^(j-1), where (2^(k-1),2^(j-1)) is the least pair of distinct positive powers of 2 for which n divides 2^(k-1)-2^(j-1).

n	a(n)
1	1
2	2
3	3
4	4
5	15
6	6
7	7
8	8
9	63
10	30
11	1023
12	12
13	4095
14	14
15	15
16	16
17	255
18	126
19	262143
20	60
21	63
22	2046
23	2047
24	24
25	1048575
26	8190
27	262143
28	28
29	268435455
30	30
31	31
32	32
33	1023
34	510
35	4095
36	252
37	68719476735
38	524286
39	4095
40	120
41	1048575
42	126
43	16383
44	4092
45	4095

[1, 2, 3, 4, 15, 6, 7, 8, 63, 30, 1023, 12, 4095, 14, 15, 16, 255, 126, 262143, 60, 63, 2046, 2047, 24, 1048575, 8190, 262143, 28, 268435455, 30, 31, 32, 1023, 510, 4095, 252, 68719476735, 524286, 4095, 120, 1048575, 126, 16383, 4092, 4095]

cp's OEIS Frontend

A204983 a(n) = 2^(k-1)-2^(j-1), where (2^(k-1),2^(j-1)) is the least pair of distinct positive powers of 2 for which n divides 2^(k-1)-2^(j-1).

Table of values

List of values