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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 15 |
| 6 | 240 |
| 7 | 15120 |
| 8 | 672 |
| 9 | 8400 |
| 10 | 100800 |
| 11 | 69300 |
| 12 | 4950 |
| 13 | 17199000 |
| 14 | 22422400 |
| 15 | 33633600 |
| 16 | 201801600 |
| 17 | 467812800 |
| 18 | 102918816000 |
| 19 | 410646075840 |
| 20 | 3555377280 |
| 21 | 215100325440 |
| 22 | 5162407810560 |
| 23 | 30920671782000 |
| 24 | 190281057120 |
| 25 | 1085315579548200 |
| 26 | 562756226432400 |
| 27 | 22969641895200 |
[1,2,4,8,15,240,15120,672,8400,100800,69300,4950, 17199000,22422400,33633600,201801600,467812800, 102918816000,410646075840,3555377280,215100325440, 5162407810560,30920671782000,190281057120, 1085315579548200,562756226432400,22969641895200] |