A026092 - OEIS

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A026092 as a simple table

n	a(n)
1	1
2	1
3	9
4	45
5	248
6	1377
7	7756
8	44096
9	252570
10	1455166
11	8424011
12	48960606
13	285512823
14	1669721225
15	9788890230
16	57511916805
17	338536358979
18	1996103321754
19	11787262391390
20	69699393574522

[1,1,9,45,248,1377,7756,44096,252570,1455166, 8424011,48960606,285512823,1669721225,9788890230, 57511916805,338536358979,1996103321754, 11787262391390,69699393574522]