A049923 - cp's OEIS frontend

A049923 a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = 2*n - 2 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 3, and a(3) = 2.

n	a(n)
1	1
2	3
3	2
4	3
5	6
6	12
7	24
8	39
9	51
10	138
11	276
12	543
13	1059
14	2019
15	3633
16	5790
17	7809
18	21405
19	42810
20	85611
21	171195
22	342291
23	684177
24	1366878
25	2729985
26	5444355
27	10824504
28	21392328
29	41760069
30	79442661
31	142937349
32	227824365
33	307267026
34	842358414

[1, 3, 2, 3, 6, 12, 24, 39, 51, 138, 276, 543, 1059, 2019, 3633, 5790, 7809, 21405, 42810, 85611, 171195, 342291, 684177, 1366878, 2729985, 5444355, 10824504, 21392328, 41760069, 79442661, 142937349, 227824365, 307267026, 842358414]

cp's OEIS Frontend

A049923 a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = 2*n - 2 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 3, and a(3) = 2.

Table of values

List of values