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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 14 |
| 4 | 50 |
| 5 | 220 |
| 6 | 1107 |
| 7 | 6030 |
| 8 | 34643 |
| 9 | 207704 |
| 10 | 1293190 |
| 11 | 8332942 |
| 12 | 55406884 |
| 13 | 379151494 |
| 14 | 2664359328 |
| 15 | 19193917324 |
| 16 | 141571867121 |
| 17 | 1068156408852 |
| 18 | 8238449274801 |
| 19 | 64921172524532 |
| 20 | 522489723684089 |
| 21 | 4293039694194962 |
| 22 | 36000331681298631 |
| 23 | 308011504511924924 |
| 24 | 2687885268655409430 |
| 25 | 23916543285143972648 |
| 26 | 216912090405180557549 |
[1,2,5,14,50,220,1107,6030,34643,207704,1293190, 8332942,55406884,379151494,2664359328,19193917324, 141571867121,1068156408852,8238449274801, 64921172524532,522489723684089,4293039694194962, 36000331681298631,308011504511924924, 2687885268655409430,23916543285143972648, 216912090405180557549] |