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 | 7 |
| 2 | 45 |
| 3 | 291 |
| 4 | 1917 |
| 5 | 12867 |
| 6 | 87805 |
| 7 | 607747 |
| 8 | 4257789 |
| 9 | 30140419 |
| 10 | 215277565 |
| 11 | 1549615107 |
| 12 | 11230642173 |
| 13 | 81882660867 |
| 14 | 600196448253 |
| 15 | 4420404117507 |
| 16 | 32695452696573 |
| 17 | 242766809923587 |
| 18 | 1808890431799293 |
| 19 | 13521381274681347 |