A117403 - OEIS

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A117403 as a simple table

n	a(n)
0	1
1	1
2	2
3	3
4	6
5	13
6	34
7	105
8	386
9	1681
10	8706
11	53793
12	395266
13	3442753
14	35659778
15	440672385
16	6476038146
17	112812130561
18	2336999211010
19	57759810847233
20	1697654543745026
21	59146046307566593
22	2450521284684021762

[1,1,2,3,6,13,34,105,386,1681,8706,53793,395266, 3442753,35659778,440672385,6476038146, 112812130561,2336999211010,57759810847233, 1697654543745026,59146046307566593, 2450521284684021762]