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 | 1 |
| 3 | 3 |
| 4 | 8 |
| 5 | 23 |
| 6 | 68 |
| 7 | 215 |
| 8 | 680 |
| 9 | 2226 |
| 10 | 7327 |
| 11 | 24607 |
| 12 | 83060 |
| 13 | 284046 |
| 14 | 975950 |
| 15 | 3383343 |
| 16 | 11778308 |
| 17 | 41269252 |
| 18 | 145131502 |
| 19 | 512881550 |
| 20 | 1818259952 |
| 21 | 6470758289 |
| 22 | 23091680690 |
| 23 | 82659905947 |
| 24 | 296605398856 |
| 25 | 1067012168350 |
| 26 | 3846553544904 |
| 27 | 13896522968160 |
| 28 | 50296815014780 |
| 29 | 182378110257354 |
| 30 | 662384549806938 |