A001991 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A001991 as a simple table

n	a(n)
1	2
2	2
3	2
4	2
5	2
6	2
7	2
8	2
9	46
10	46
11	46
12	46
13	46
14	46
15	406
16	718
17	950
18	950
19	950
20	1698
21	1698
22	1698
23	1698
24	1698
25	3990
26	3990
27	3990
28	53510
29	77970
30	89478
31	89478
32	89478
33	89478
34	89478
35	89478

[2,2,2,2,2,2,2,2,46,46,46,46,46,46,406,718,950, 950,950,1698,1698,1698,1698,1698,3990,3990,3990, 53510,77970,89478,89478,89478,89478,89478,89478]