This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 15 |
| 5 | 238 |
| 6 | 2401 |
| 7 | 22084 |
| 8 | 202922 |
| 9 | 1824043 |
| 10 | 16296072 |
| 11 | 145357801 |
| 12 | 1298682892 |
| 13 | 11638466683 |
| 14 | 104682551230 |
| 15 | 945244226939 |
| 16 | 8568535834789 |
| 17 | 77968773245740 |
| 18 | 712064159940996 |