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A127691 as a simple table

n a(n)
0 -1
1 0
2 0
3 2
4 64
5 2002
6 69264
7 2697354
8 117899520
9 5740530914
10 308814720400
11 18213955960378
12 1169672907313728
13 81286160430474066
14 6080123714344570128
15 487166244246501489002
16 41636260100744439399424
17 3781449867356996500139458
18 363724112817207189865471248

[-1,0,0,2,64,2002,69264,2697354,117899520,
 5740530914,308814720400,18213955960378,
 1169672907313728,81286160430474066,
 6080123714344570128,487166244246501489002,
 41636260100744439399424,3781449867356996500139458,
 363724112817207189865471248]

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Last modified December 7 10:26 EST 2022. Contains 358656 sequences. (Running on oeis4.)