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 | 1 |
| 3 | 3 |
| 4 | 11 |
| 5 | 69 |
| 6 | 602 |
| 7 | 6531 |
| 8 | 84737 |
| 9 | 1271143 |
| 10 | 21623667 |
| 11 | 411133711 |
| 12 | 8639077230 |
| 13 | 198801435313 |
| 14 | 4972210166209 |
| 15 | 134299831740091 |
| 16 | 3895950849227855 |
| 17 | 120808412263797173 |
| 18 | 3987662458459383826 |
| 19 | 139598735205063044939 |