A131726 - 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

A131726 as a simple table

n	a(n)
0	0
1	0
2	0
3	0
4	10
5	20
6	70
7	160
8	400
9	980
10	2370
11	5740
12	13860
13	33460
14	80780
15	195020
16	470830
17	1136680
18	2744210
19	6625100
20	15994420
21	38613960

[0,0,0,0,10,20,70,160,400,980,2370,5740,13860, 33460,80780,195020,470830,1136680,2744210,6625100, 15994420,38613960]