A049901 - cp's OEIS frontend

A049901 a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 2, and a(3) = 1.

n	a(n)
1	1
2	2
3	1
4	2
5	5
6	9
7	19
8	37
9	75
10	114
11	246
12	502
13	1008
14	2019
15	4039
16	8077
17	16155
18	24234
19	52506
20	107032
21	215075
22	430656
23	861568
24	1723268
25	3446575
26	6893188
27	13786394
28	27572798
29	55145600
30	110291203
31	220582407
32	441164813
33	882329627
34	1323494442

[1, 2, 1, 2, 5, 9, 19, 37, 75, 114, 246, 502, 1008, 2019, 4039, 8077, 16155, 24234, 52506, 107032, 215075, 430656, 861568, 1723268, 3446575, 6893188, 13786394, 27572798, 55145600, 110291203, 220582407, 441164813, 882329627, 1323494442]

cp's OEIS Frontend

A049901 a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 2, and a(3) = 1.

Table of values

List of values