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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 8 |
| 6 | 32 |
| 7 | 114 |
| 8 | 376 |
| 9 | 1177 |
| 10 | 3549 |
| 11 | 10406 |
| 12 | 29861 |
| 13 | 84249 |
| 14 | 234502 |
| 15 | 645625 |
| 16 | 1761765 |
| 17 | 4772534 |
| 18 | 12851261 |
| 19 | 34434561 |
| 20 | 91890118 |
| 21 | 244385617 |
| 22 | 648139821 |
| 23 | 1714976054 |
| 24 | 4529163125 |
| 25 | 11942440233 |
| 26 | 31448759302 |
| 27 | 82727323369 |
| 28 | 217426319541 |
| 29 | 571033273142 |