A147212 - 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

A147212 as a simple table

n	a(n)
1	1
2	1
3	1
4	1
5	3
6	9
7	23
8	55
9	315
10	2117
11	14227
12	107639
13	1242577
14	18337443
15	306941589
16	6236872411
17	166949397689
18	5617277183949
19	229023263912585
20	11581498844555427

[1,1,1,1,3,9,23,55,315,2117,14227,107639,1242577, 18337443,306941589,6236872411,166949397689, 5617277183949,229023263912585,11581498844555427]