A013449 - OEIS

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A013449 as a simple table

n	a(n)
0	1
1	0
2	0
3	1
4	0
5	15
6	10
7	271
8	840
9	8215
10	60870
11	423091
12	4980580
13	35126715
14	501501130
15	4192844111
16	63445348720
17	652228720015
18	10063325322190
19	125163350892331
20	1976669210391260
21	28804173376146115

[1,0,0,1,0,15,10,271,840,8215,60870,423091, 4980580,35126715,501501130,4192844111,63445348720, 652228720015,10063325322190,125163350892331, 1976669210391260,28804173376146115]