A081972 - OEIS

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A081972 as a simple table

n	a(n)
1	1
2	1
3	4
4	34
5	528
6	16644
7	1056832
8	134744072
9	34426978560
10	17609382707216
11	18023198899569664
12	36902497546234101792
13	151134176447977081540608
14	1238015601761073699807559744
15	20283028592561355523908308058112

[1,1,4,34,528,16644,1056832,134744072,34426978560, 17609382707216,18023198899569664, 36902497546234101792,151134176447977081540608, 1238015601761073699807559744, 20283028592561355523908308058112]