A007193 - OEIS

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A007193 as a simple table

n	a(n)
1	1
2	6
3	45
4	365
5	3101
6	27144
7	242636
8	2202873
9	20241055
10	187766940
11	1755409652
12	16517284570
13	156265005369
14	1485269469971
15	14174126304850
16	135741870538293
17	1303996171096108
18	12561249340326373
19	121298814197201725

[1,6,45,365,3101,27144,242636,2202873,20241055, 187766940,1755409652,16517284570,156265005369, 1485269469971,14174126304850,135741870538293, 1303996171096108,12561249340326373, 121298814197201725]