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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 10 |
| 5 | 26 |
| 6 | 166 |
| 7 | 652 |
| 8 | 3795 |
| 9 | 18755 |
| 10 | 112124 |
| 11 | 648649 |
| 12 | 4163743 |
| 13 | 27216840 |
| 14 | 190168577 |
| 15 | 1376119903 |
| 16 | 10468226150 |
| 17 | 82744297014 |
| 18 | 681863474058 |
| 19 | 5830425411936 |
| 20 | 51720008131148 |
| 21 | 474821737584174 |
| 22 | 4506628734688128 |
| 23 | 44150936144057758 |
| 24 | 445956917001833090 |
| 25 | 4638564968368158592 |
[1,0,1,1,10,26,166,652,3795,18755,112124,648649, 4163743,27216840,190168577,1376119903,10468226150, 82744297014,681863474058,5830425411936, 51720008131148,474821737584174,4506628734688128, 44150936144057758,445956917001833090, 4638564968368158592] |