A172531 - OEIS

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A172531 as a simple table

n	a(n)
1	0
2	0
3	0
4	228
5	600
6	12357
7	68796
8	275888
9	872532
10	2344025
11	5580762
12	12107196
13	24392446
14	46261537
15	83426400
16	144157632
17	240119696
18	387393921
19	607715342
20	929951100

[0,0,0,228,600,12357,68796,275888,872532,2344025, 5580762,12107196,24392446,46261537,83426400, 144157632,240119696,387393921,607715342,929951100]