A209361 - 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

A209361 as a simple table

n	a(n)
1	1
2	2
3	16
4	122
5	690
6	4098
7	24301
8	131984
9	720033
10	3945050
11	21470933
12	115976303
13	629975658
14	3432416744
15	18721854079
16	102389248936
17	560740694837
18	3070272326544
19	16802201754590
20	91916873329401
21	502611764211182

[1,2,16,122,690,4098,24301,131984,720033,3945050, 21470933,115976303,629975658,3432416744, 18721854079,102389248936,560740694837, 3070272326544,16802201754590,91916873329401, 502611764211182]