| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 13 |
| 5 | 31 |
| 6 | 76 |
| 7 | 211 |
| 8 | 589 |
| 9 | 1597 |
| 10 | 4351 |
| 11 | 12046 |
| 12 | 33496 |
| 13 | 93094 |
| 14 | 259351 |
| 15 | 725089 |
| 16 | 2031709 |
| 17 | 5701189 |
| 18 | 16023181 |
| 19 | 45104044 |
| 20 | 127134283 |
| 21 | 358764613 |
| 22 | 1013494318 |
| 23 | 2865933907 |
| 24 | 8111573416 |
| 25 | 22977551656 |
| 26 | 65138143006 |
| 27 | 184789086106 |
| 28 | 524571000799 |
| 29 | 1490044262503 |
| 30 | 4234901256781 |
| 31 | 12042611698876 |
| 32 | 34262320521661 |
| 33 | 97525522430989 |
[1,1,1,4,13,31,76,211,589,1597,4351,12046,33496, 93094,259351,725089,2031709,5701189,16023181, 45104044,127134283,358764613,1013494318, 2865933907,8111573416,22977551656,65138143006, 184789086106,524571000799,1490044262503, 4234901256781,12042611698876,34262320521661, 97525522430989] |