A097581 - cp's OEIS frontend

A097581 a(n) = 3*2^floor((n-1)/2) + (-1)^n.

n	a(n)
1	2
2	4
3	5
4	7
5	11
6	13
7	23
8	25
9	47
10	49
11	95
12	97
13	191
14	193
15	383
16	385
17	767
18	769
19	1535
20	1537
21	3071
22	3073
23	6143
24	6145
25	12287
26	12289
27	24575
28	24577
29	49151
30	49153
31	98303
32	98305
33	196607
34	196609
35	393215
36	393217
37	786431
38	786433
39	1572863
40	1572865

[2, 4, 5, 7, 11, 13, 23, 25, 47, 49, 95, 97, 191, 193, 383, 385, 767, 769, 1535, 1537, 3071, 3073, 6143, 6145, 12287, 12289, 24575, 24577, 49151, 49153, 98303, 98305, 196607, 196609, 393215, 393217, 786431, 786433, 1572863, 1572865]

cp's OEIS Frontend

A097581 a(n) = 3*2^floor((n-1)/2) + (-1)^n.

Table of values

List of values