A081026 - cp's OEIS frontend

A081026 Variation on Ulam numbers: a(1) = 1; a(2) = 2; for n>2, a(n) = smallest (n odd) or largest (n even) number > a(n-1) that is a unique sum of two distinct earlier terms.

n	a(n)
1	1
2	2
3	3
4	5
5	6
6	11
7	12
8	23
9	24
10	47
11	48
12	95
13	96
14	191
15	192
16	383
17	384
18	767
19	768
20	1535
21	1536
22	3071
23	3072
24	6143
25	6144
26	12287
27	12288
28	24575
29	24576
30	49151
31	49152
32	98303
33	98304
34	196607
35	196608
36	393215
37	393216
38	786431
39	786432
40	1572863
41	1572864
42	3145727

[1, 2, 3, 5, 6, 11, 12, 23, 24, 47, 48, 95, 96, 191, 192, 383, 384, 767, 768, 1535, 1536, 3071, 3072, 6143, 6144, 12287, 12288, 24575, 24576, 49151, 49152, 98303, 98304, 196607, 196608, 393215, 393216, 786431, 786432, 1572863, 1572864, 3145727]

cp's OEIS Frontend

A081026 Variation on Ulam numbers: a(1) = 1; a(2) = 2; for n>2, a(n) = smallest (n odd) or largest (n even) number > a(n-1) that is a unique sum of two distinct earlier terms.

Table of values

List of values