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 | 2 |
| 4 | 7 |
| 5 | 26 |
| 6 | 144 |
| 7 | 800 |
| 8 | 4995 |
| 9 | 32176 |
| 10 | 215914 |
| 11 | 1486270 |
| 12 | 10471534 |
| 13 | 75137664 |
| 14 | 547756650 |
| 15 | 4047212142 |
| 16 | 30255934851 |
| 17 | 228513227318 |
| 18 | 1741572167716 |
| 19 | 13380306774014 |
| 20 | 103542814440878 |
| 21 | 806476983310180 |
| 22 | 6318519422577854 |
| 23 | 49769050291536486 |
| 24 | 393933908000862866 |