| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 15 |
| 2 | 119 |
| 3 | 665 |
| 4 | 2939 |
| 5 | 10933 |
| 6 | 35580 |
| 7 | 103972 |
| 8 | 277950 |
| 9 | 689282 |
| 10 | 1602727 |
| 11 | 3523945 |
| 12 | 7376794 |
| 13 | 14784390 |
| 14 | 28500705 |
| 15 | 53054702 |
| 16 | 95687240 |
| 17 | 167682306 |
| 18 | 286218490 |
| 19 | 476893794 |
| 20 | 777106448 |
| 21 | 1240505775 |
| 22 | 1942759458 |
| 23 | 2988915740 |
| 24 | 4522669833 |
[1,15,119,665,2939,10933,35580,103972,277950, 689282,1602727,3523945,7376794,14784390,28500705, 53054702,95687240,167682306,286218490,476893794, 777106448,1240505775,1942759458,2988915740, 4522669833] |