A069990 - OEIS

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A069990 as a simple table

n	a(n)
1	1
2	15
3	389
4	17687
5	1230957
6	121576879
7	16166877205
8	2784640846791
9	603078760252733
10	160399574539581023
11	51396542533525536741
12	19528343388372578867575
13	8681260357657270101974029

[1,15,389,17687,1230957,121576879,16166877205, 2784640846791,603078760252733,160399574539581023, 51396542533525536741,19528343388372578867575, 8681260357657270101974029]