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 | 1 |
| 3 | 4 |
| 4 | 12 |
| 5 | 35 |
| 6 | 99 |
| 7 | 274 |
| 8 | 747 |
| 9 | 2015 |
| 10 | 5394 |
| 11 | 14359 |
| 12 | 38067 |
| 13 | 100610 |
| 14 | 265299 |
| 15 | 698359 |
| 16 | 1835922 |
| 17 | 4821695 |
| 18 | 12653739 |
| 19 | 33188674 |
| 20 | 87010587 |
| 21 | 228039695 |
| 22 | 597501714 |
| 23 | 1565251879 |
| 24 | 4099826787 |
| 25 | 10737374210 |
| 26 | 28118587299 |
| 27 | 73630970599 |
| 28 | 192799490322 |
| 29 | 504817832015 |