A049891 - cp's OEIS frontend

A049891 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) = a(2) = 1 and a(3) = 2.

n	a(n)
1	1
2	1
3	2
4	3
5	4
6	10
7	18
8	29
9	39
10	106
11	210
12	413
13	807
14	1537
15	2767
16	4410
17	5947
18	16303
19	32604
20	65201
21	130383
22	260689
23	521071
24	1041018
25	2079163
26	4146433
27	8243968
28	16292448
29	31804567
30	60503719
31	108861423
32	173511575
33	234015294
34	641542162

[1, 1, 2, 3, 4, 10, 18, 29, 39, 106, 210, 413, 807, 1537, 2767, 4410, 5947, 16303, 32604, 65201, 130383, 260689, 521071, 1041018, 2079163, 4146433, 8243968, 16292448, 31804567, 60503719, 108861423, 173511575, 234015294, 641542162]

cp's OEIS Frontend

A049891 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) = a(2) = 1 and a(3) = 2.

Table of values

List of values