A168043 - cp's OEIS frontend

A168043 Let S(1)={1} and, for n>1 let S(n) be the smallest set containing x+1, x+2, and 2*x for each element x in S(n-1). a(n) is the number of elements in S(n).

n	a(n)
1	1
2	2
3	4
4	7
5	13
6	23
7	40
8	68
9	114
10	189
11	311
12	509
13	830
14	1350
15	2192
16	3555
17	5761
18	9331
19	15108
20	24456
21	39582
22	64057
23	103659
24	167737
25	271418
26	439178
27	710620
28	1149823
29	1860469
30	3010319
31	4870816
32	7881164
33	12752010
34	20633205
35	33385247
36	54018485
37	87403766
38	141422286

[1, 2, 4, 7, 13, 23, 40, 68, 114, 189, 311, 509, 830, 1350, 2192, 3555, 5761, 9331, 15108, 24456, 39582, 64057, 103659, 167737, 271418, 439178, 710620, 1149823, 1860469, 3010319, 4870816, 7881164, 12752010, 20633205, 33385247, 54018485, 87403766, 141422286]

cp's OEIS Frontend

A168043 Let S(1)={1} and, for n>1 let S(n) be the smallest set containing x+1, x+2, and 2*x for each element x in S(n-1). a(n) is the number of elements in S(n).

Table of values

List of values