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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 9 |
| 4 | 20 |
| 5 | 45 |
| 6 | 102 |
| 7 | 230 |
| 8 | 516 |
| 9 | 1158 |
| 10 | 2599 |
| 11 | 5831 |
| 12 | 13082 |
| 13 | 29351 |
| 14 | 65853 |
| 15 | 147748 |
| 16 | 331490 |
| 17 | 743735 |
| 18 | 1668650 |
| 19 | 3743800 |
| 20 | 8399623 |
| 21 | 18845471 |
| 22 | 42281871 |
| 23 | 94863989 |
| 24 | 212837706 |
| 25 | 477524607 |
| 26 | 1071378536 |
| 27 | 2403754591 |
| 28 | 5393085583 |
| 29 | 12099975682 |
| 30 | 27147615084 |
| 31 | 60908635199 |
| 32 | 136655165852 |
[1,4,9,20,45,102,230,516,1158,2599,5831,13082, 29351,65853,147748,331490,743735,1668650,3743800, 8399623,18845471,42281871,94863989,212837706, 477524607,1071378536,2403754591,5393085583, 12099975682,27147615084,60908635199,136655165852] |