A006540 - OEIS

A006540 as a simple table

n	a(n)
0	1
1	3
2	5
3	7
4	7
5	13
6	19
7	23
8	31
9	47
10	61
11	71
12	73
13	121
14	121
15	121
16	121
17	121
18	121
19	242
20	484
21	661
22	661
23	661
24	1093
25	1753
26	1807
27	3053
28	3613
29	3613
30	3613
31	5461
32	5461
33	8011
34	8011
35	8011
36	8011
37	10081
38	16381

[1,3,5,7,7,13,19,23,31,47,61,71,73,121,121,121, 121,121,121,242,484,661,661,661,1093,1753,1807, 3053,3613,3613,3613,5461,5461,8011,8011,8011,8011, 10081,16381]