A009840 - OEIS

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A009840 as a simple table

n	a(n)
0	1
1	1
2	1
3	-167
4	289
5	-30799
6	7624865
7	-327166135
8	29995758529
9	-7060555404191
10	991934013190081
11	-177889548504511175
12	51940497621294961121
13	-14246314907147632709615
14	4386830634217402797858657

[1,1,1,-167,289,-30799,7624865,-327166135, 29995758529,-7060555404191,991934013190081, -177889548504511175,51940497621294961121, -14246314907147632709615, 4386830634217402797858657]