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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 6 |
| 3 | 50 |
| 4 | 518 |
| 5 | 6354 |
| 6 | 89782 |
| 7 | 1435330 |
| 8 | 25625910 |
| 9 | 505785122 |
| 10 | 10944711398 |
| 11 | 257834384850 |
| 12 | 6572585595622 |
| 13 | 180334118225650 |
| 14 | 5300553714899094 |
| 15 | 166206234856979810 |
| 16 | 5538980473666776854 |
| 17 | 195527829569946627138 |
| 18 | 7288988096561232432070 |