A382646 - cp's OEIS frontend

A382646 Numbers k such that (k2^d - 1)(d*2^k - 1) is semiprime for some divisor d of k.

n	a(n)
1	2
2	3
3	6
4	7
5	12
6	18
7	19
8	21
9	30
10	31
11	42
12	60
13	75
14	81
15	115
16	123
17	126
18	132
19	133
20	225
21	249
22	306
23	324
24	362
25	384
26	462
27	468
28	512
29	606
30	607
31	612
32	751
33	822
34	1279
35	2170
36	2202
37	2281
38	5312
39	7755
40	9531
41	12379
42	14898
43	15822
44	18123
45	18819
46	18885
47	22971
48	23005
49	23208
50	41628
51	44497
52	51384
53	52540
54	98726

[2, 3, 6, 7, 12, 18, 19, 21, 30, 31, 42, 60, 75, 81, 115, 123, 126, 132, 133, 225, 249, 306, 324, 362, 384, 462, 468, 512, 606, 607, 612, 751, 822, 1279, 2170, 2202, 2281, 5312, 7755, 9531, 12379, 14898, 15822, 18123, 18819, 18885, 22971, 23005, 23208, 41628, 44497, 51384, 52540, 98726]

cp's OEIS Frontend

A382646 Numbers k such that (k2^d - 1)(d*2^k - 1) is semiprime for some divisor d of k.

Table of values

List of values

cp's OEIS Frontend

A382646 Numbers k such that (k*2^d - 1)*(d*2^k - 1) is semiprime for some divisor d of k.

Table of values

List of values

A382646 Numbers k such that (k2^d - 1)(d*2^k - 1) is semiprime for some divisor d of k.