A371621-OEIS公司

A371621型作为一个简单的表

n个	a（n）
0	1
1	1
2	1
三	2
4	4
5	-10
6	-130
7	-840
8	-5880
9	-36960
10	-142800
11	184800
12	12843600
13	229429200
14	3035432400
15	31615584000
16	258306048000
17	943422480000
18	-26673126480000
19	-902769547680000
20	-18345450483360000
21	-300501672831360000
22	-3983084426280960000

[1,1,1,2,4,-10,-130,-840,-5880,-36960,-142800,184800,12843600,229429200,3035432400,31615584000,258306048000,943422480000,-26673126480000,-902769547680000,-18345450483360000,-300501672831360000,-3983084426280960000]