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 | 0 |
| 1 | 1 |
| 2 | 17 |
| 3 | 217 |
| 4 | 2465 |
| 5 | 26281 |
| 6 | 269297 |
| 7 | 2685817 |
| 8 | 26269505 |
| 9 | 253202761 |
| 10 | 2413042577 |
| 11 | 22791125017 |
| 12 | 213710059745 |
| 13 | 1992110014441 |
| 14 | 18478745943857 |
| 15 | 170706760005817 |
| 16 | 1571545212141185 |
| 17 | 14425381885981321 |
| 18 | 132080236787517137 |
| 19 | 1206736529597136217 |
| 20 | 11004743954450081825 |