A128823 - OEIS

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A128823 as a simple table

n	a(n)
1	20
2	212
3	2351
4	15127
5	178707
6	1981891
7	21979508
8	141422324
9	1670731762
10	18528699171
11	205486422643
12	2278879348244
13	14662949395604
14	173224810531570
15	1921092587268915
16	21305243270489635
17	236278768562654900

[20,212,2351,15127,178707,1981891,21979508, 141422324,1670731762,18528699171,205486422643, 2278879348244,14662949395604,173224810531570, 1921092587268915,21305243270489635, 236278768562654900]