A049938 - cp's OEIS frontend

A049938 a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = n - 1 - 2^p and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), with a(1) = a(2) = 1 and a(3) = 2.

n	a(n)
1	1
2	1
3	2
4	5
5	10
6	20
7	40
8	81
9	165
10	326
11	652
12	1305
13	2613
14	5231
15	10472
16	20964
17	41969
18	83858
19	167716
20	335433
21	670869
22	1341743
23	2683496
24	5367012
25	10734065
26	21468214
27	42936589
28	85873504
29	171747661
30	343496630
31	686995878
32	1373996997
33	2748004486
34	5495988009
35	10991976018
36	21983952037
37	43967904077

[1, 1, 2, 5, 10, 20, 40, 81, 165, 326, 652, 1305, 2613, 5231, 10472, 20964, 41969, 83858, 167716, 335433, 670869, 1341743, 2683496, 5367012, 10734065, 21468214, 42936589, 85873504, 171747661, 343496630, 686995878, 1373996997, 2748004486, 5495988009, 10991976018, 21983952037, 43967904077]

cp's OEIS Frontend

A049938 a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = n - 1 - 2^p and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), with a(1) = a(2) = 1 and a(3) = 2.

Table of values

List of values