A056448 - 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

A056448 as a simple table

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	1
7	1
8	18
9	59
10	630
11	1681
12	28866
13	60083
14	757576
15	3514504
16	21423984
17	64372109
18	1024999170
19	2026631203
20	26920954613
21	105501588414
22	742299897060
23	1974251382095
24	31721456288956
25	74052852505684

[0,0,0,0,0,1,1,18,59,630,1681,28866,60083,757576, 3514504,21423984,64372109,1024999170,2026631203, 26920954613,105501588414,742299897060, 1974251382095,31721456288956,74052852505684]