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 | 3 |
| 3 | 13 |
| 4 | 63 |
| 5 | 324 |
| 6 | 1736 |
| 7 | 9589 |
| 8 | 54223 |
| 9 | 312369 |
| 10 | 1826847 |
| 11 | 10818156 |
| 12 | 64737684 |
| 13 | 390877456 |
| 14 | 2378312780 |
| 15 | 14568360645 |
| 16 | 89766137967 |
| 17 | 556008951667 |
| 18 | 3459976045201 |
| 19 | 21621154097573 |
| 20 | 135619427912599 |
| 21 | 853590782088272 |
| 22 | 5389272616262656 |
| 23 | 34123058549079788 |
| 24 | 216621704634708868 |