A013451 - OEIS

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A013451 as a simple table

n	a(n)
0	1
1	0
2	0
3	4
4	0
5	0
6	160
7	544
8	0
9	17920
10	261120
11	707584
12	3942400
13	149360640
14	1538068480
15	5242548224
16	111522611200
17	2782416732160
18	25458261360640
19	166243180478464
20	5279051703910400
21	109528131284500480

[1,0,0,4,0,0,160,544,0,17920,261120,707584, 3942400,149360640,1538068480,5242548224, 111522611200,2782416732160,25458261360640, 166243180478464,5279051703910400, 109528131284500480]