| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 33 |
| 4 | 180 |
| 5 | 1071 |
| 6 | 6776 |
| 7 | 44907 |
| 8 | 308903 |
| 9 | 2192218 |
| 10 | 15986187 |
| 11 | 119458754 |
| 12 | 913085921 |
| 13 | 7130596660 |
| 14 | 56856959415 |
| 15 | 462789536503 |
| 16 | 3845600755712 |
| 17 | 32634320897898 |
| 18 | 282973974102022 |
| 19 | 2508805646347474 |
| 20 | 22758825619762568 |
| 21 | 211400392340768128 |
| 22 | 2011934295358876840 |
| 23 | 19628847839908163287 |
| 24 | 196377194100036473222 |
| 25 | 2014897715206819032244 |
| 26 | 21199978342486061320347 |
| 27 | 228666292563823622317191 |
[1,2,7,33,180,1071,6776,44907,308903,2192218, 15986187,119458754,913085921,7130596660, 56856959415,462789536503,3845600755712, 32634320897898,282973974102022,2508805646347474, 22758825619762568,211400392340768128, 2011934295358876840,19628847839908163287, 196377194100036473222,2014897715206819032244, 21199978342486061320347,228666292563823622317191] |