A007679 - cp's OEIS frontend

A007679 If n mod 4 = 0 then 2^(n-1)+1 elif n mod 4 = 2 then 2^(n-1)-1 else 2^(n-1).

n	a(n)
1	1
2	1
3	4
4	9
5	16
6	31
7	64
8	129
9	256
10	511
11	1024
12	2049
13	4096
14	8191
15	16384
16	32769
17	65536
18	131071
19	262144
20	524289
21	1048576
22	2097151
23	4194304
24	8388609
25	16777216
26	33554431
27	67108864
28	134217729
29	268435456
30	536870911

[1, 1, 4, 9, 16, 31, 64, 129, 256, 511, 1024, 2049, 4096, 8191, 16384, 32769, 65536, 131071, 262144, 524289, 1048576, 2097151, 4194304, 8388609, 16777216, 33554431, 67108864, 134217729, 268435456, 536870911]

cp's OEIS Frontend

A007679 If n mod 4 = 0 then 2^(n-1)+1 elif n mod 4 = 2 then 2^(n-1)-1 else 2^(n-1).

Table of values

List of values