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 | 1 |
| 2 | 3 |
| 3 | 14 |
| 4 | 81 |
| 5 | 527 |
| 6 | 3684 |
| 7 | 27022 |
| 8 | 205149 |
| 9 | 1598303 |
| 10 | 12705939 |
| 11 | 102653652 |
| 12 | 840419676 |
| 13 | 6956988612 |
| 14 | 58132229976 |
| 15 | 489673597926 |
| 16 | 4153635860373 |
| 17 | 35449185841679 |
| 18 | 304179698619129 |
| 19 | 2622657870000646 |
| 20 | 22710277017073785 |
| 21 | 197418128701387895 |