A137960 - 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

A137960 as a simple table

n	a(n)
0	1
1	1
2	2
3	11
4	50
5	275
6	1560
7	9212
8	56082
9	348675
10	2207120
11	14171155
12	92075064
13	604266000
14	3999688050
15	26670727220
16	178997024610
17	1208160130227
18	8195828345756
19	55849242272130
20	382119958804520
21	2624041637846210

[1,1,2,11,50,275,1560,9212,56082,348675,2207120, 14171155,92075064,604266000,3999688050, 26670727220,178997024610,1208160130227, 8195828345756,55849242272130,382119958804520, 2624041637846210]