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A156757 as a simple table

na(n)
01
1-1
2-99
3299
449401
5-249001
6-60251499
7425252099
8136795497201
9-1241382296401
10-498990299504499
115534485665505499
122669489641160743401
13-34991633084859742201
14-19690651784477632959099
15297813229679687736760499
16191527704666360326602988001

[1,-1,-99,299,49401,-249001,-60251499,425252099,
 136795497201,-1241382296401,-498990299504499,
 5534485665505499,2669489641160743401,
 -34991633084859742201,-19690651784477632959099,
 297813229679687736760499,
 191527704666360326602988001]