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Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 13 |
| 5 | 63 |
| 6 | 360 |
| 7 | 2612 |
| 8 | 20628 |
| 9 | 184784 |
| 10 | 1814400 |
| 11 | 20168640 |
| 12 | 241650132 |
| 13 | 3135712971 |
| 14 | 43589145600 |
| 15 | 657203494738 |
| 16 | 10507402233956 |
| 17 | 178516252664449 |
| 18 | 3201186852864000 |
| 19 | 60997137390971895 |
| 20 | 1219540642469803416 |
| 21 | 25602927723893352601 |
| 22 | 562000363888803840000 |
[1,1,3,13,63,360,2612,20628,184784,1814400, 20168640,241650132,3135712971,43589145600, 657203494738,10507402233956,178516252664449, 3201186852864000,60997137390971895, 1219540642469803416,25602927723893352601, 562000363888803840000] |