A189852 - 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

A189852 as a simple table

n	a(n)
1	1
2	2
3	6
4	24
5	120
6	336
7	1474
8	8340
9	57756
10	475658
11	2812910
12	20852460
13	181255892
14	1817101242
15	20435345782
16	197871434994

[1,2,6,24,120,336,1474,8340,57756,475658,2812910, 20852460,181255892,1817101242,20435345782, 197871434994]