| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 10 |
| 3 | 52 |
| 4 | 724 |
| 5 | 970 |
| 6 | 10084 |
| 7 | 95050 |
| 8 | 140452 |
| 9 | 1956244 |
| 10 | 9313930 |
| 11 | 27246964 |
| 12 | 379501252 |
| 13 | 912670090 |
| 14 | 5285770564 |
| 15 | 73621286644 |
| 16 | 89432354890 |
| 17 | 1025412242452 |
| 18 | 8763458109130 |
| 19 | 14282150107684 |
| 20 | 198924689265124 |
[4,10,52,724,970,10084,95050,140452,1956244, 9313930,27246964,379501252,912670090,5285770564, 73621286644,89432354890,1025412242452, 8763458109130,14282150107684,198924689265124] |