A276202 - cp's OEIS frontend

A276202 Smallest integer k such that the number of semiprimes in {k, f(k), f(f(k)), ..., 1} is equal to n, where f is the Collatz function.

n	a(n)
0	1
1	4
2	3
3	6
4	11
5	7
6	14
7	9
8	25
9	33
10	59
11	57
12	39
13	135
14	191
15	127
16	123
17	159
18	219
19	379
20	251
21	167
22	223
23	111
24	793
25	263
26	175
27	466
28	103
29	137
30	183
31	91
32	121
33	107
34	71
35	47
36	31
37	41
38	27
39	97
40	145
41	129
42	171
43	231
44	235
45	553
46	411
47	487
48	327
49	649
50	703
51	763
52	1519
53	1215
54	1471
55	1071

[1, 4, 3, 6, 11, 7, 14, 9, 25, 33, 59, 57, 39, 135, 191, 127, 123, 159, 219, 379, 251, 167, 223, 111, 793, 263, 175, 466, 103, 137, 183, 91, 121, 107, 71, 47, 31, 41, 27, 97, 145, 129, 171, 231, 235, 553, 411, 487, 327, 649, 703, 763, 1519, 1215, 1471, 1071]

cp's OEIS Frontend

A276202 Smallest integer k such that the number of semiprimes in {k, f(k), f(f(k)), ..., 1} is equal to n, where f is the Collatz function.

Table of values

List of values