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 | 4 |
| 3 | 14 |
| 4 | 56 |
| 5 | 241 |
| 6 | 1080 |
| 7 | 4998 |
| 8 | 23704 |
| 9 | 114588 |
| 10 | 562552 |
| 11 | 2797138 |
| 12 | 14057140 |
| 13 | 71288385 |
| 14 | 364360204 |
| 15 | 1874960408 |
| 16 | 9706035408 |
| 17 | 50510552881 |
| 18 | 264096980192 |
| 19 | 1386676113360 |
| 20 | 7308650513232 |
| 21 | 38654087828310 |
| 22 | 205076534841112 |
| 23 | 1091144400876394 |
| 24 | 5820924498941668 |