A067857 - 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

A067857 as a simple table

n	a(n)
1	1
2	1
3	5
4	14
5	154
6	84
7	8028
8	25584
9	361296
10	528480
11	80627040
12	33471360
13	13575738240
14	13835646720
15	263577888000
16	13869128448000
17	867718162483200
18	316745643110400
19	309920046408806400
20	207862451693568000

[1,1,5,14,154,84,8028,25584,361296,528480, 80627040,33471360,13575738240,13835646720, 263577888000,13869128448000,867718162483200, 316745643110400,309920046408806400, 207862451693568000]