| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 37 |
| 3 | 174 |
| 4 | 852 |
| 5 | 5396 |
| 6 | 29773 |
| 7 | 162828 |
| 8 | 945314 |
| 9 | 5347977 |
| 10 | 30133308 |
| 11 | 171973424 |
| 12 | 977160855 |
| 13 | 5545471514 |
| 14 | 31555267875 |
| 15 | 179438125871 |
| 16 | 1020048459286 |
| 17 | 5801865031579 |
| 18 | 32997308834050 |
| 19 | 187654134511476 |
| 20 | 1067303125037252 |
[4,37,174,852,5396,29773,162828,945314,5347977, 30133308,171973424,977160855,5545471514, 31555267875,179438125871,1020048459286, 5801865031579,32997308834050,187654134511476, 1067303125037252] |