A268253 - cp's OEIS frontend

A268253 a(n) begins the first chain of 5 consecutive positive integers of h-values with symmetrical gaps about the center, where h(k) is the length of the finite sequence k, f(k), f(f(k)), ..., 1 in the Collatz (or 3x + 1) problem.

n	a(n)
1	98
2	130
3	290
4	354
5	386
6	387
7	418
8	507
9	514
10	610
11	628
12	802
13	840
14	841
15	866
16	943
17	944
18	945
19	1003
20	1121
21	1122
22	1154
23	1172
24	1186
25	1272
26	1314
27	1378
28	1442
29	1494
30	1495
31	1496
32	1497
33	1538
34	1634
35	1680
36	1681
37	1682
38	1683
39	1684
40	1698
41	1699
42	1826
43	1890
44	1922
45	1923
46	1991
47	1992

[98, 130, 290, 354, 386, 387, 418, 507, 514, 610, 628, 802, 840, 841, 866, 943, 944, 945, 1003, 1121, 1122, 1154, 1172, 1186, 1272, 1314, 1378, 1442, 1494, 1495, 1496, 1497, 1538, 1634, 1680, 1681, 1682, 1683, 1684, 1698, 1699, 1826, 1890, 1922, 1923, 1991, 1992]

cp's OEIS Frontend

A268253 a(n) begins the first chain of 5 consecutive positive integers of h-values with symmetrical gaps about the center, where h(k) is the length of the finite sequence k, f(k), f(f(k)), ..., 1 in the Collatz (or 3x + 1) problem.

Table of values

List of values