| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 7 |
| 2 | 38 |
| 3 | 187 |
| 4 | 874 |
| 5 | 3958 |
| 6 | 17548 |
| 7 | 76627 |
| 8 | 330818 |
| 9 | 1415650 |
| 10 | 6015316 |
| 11 | 25413342 |
| 12 | 106853668 |
| 13 | 447472972 |
| 14 | 1867450648 |
| 15 | 7770342787 |
| 16 | 32248174258 |
| 17 | 133530264682 |
| 18 | 551793690628 |
| 19 | 2276098026922 |
| 20 | 9373521044908 |
| 21 | 38546133661492 |
| 22 | 158301250009768 |
| 23 | 649328801880622 |
[1,7,38,187,874,3958,17548,76627,330818,1415650, 6015316,25413342,106853668,447472972,1867450648, 7770342787,32248174258,133530264682,551793690628, 2276098026922,9373521044908,38546133661492, 158301250009768,649328801880622] |