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 | 1 |
| 2 | 8 |
| 3 | 55 |
| 4 | 354 |
| 5 | 2205 |
| 6 | 13484 |
| 7 | 81523 |
| 8 | 489158 |
| 9 | 2919481 |
| 10 | 17356752 |
| 11 | 102884271 |
| 12 | 608460330 |
| 13 | 3591886293 |
| 14 | 21172419444 |
| 15 | 124649246955 |
| 16 | 733107494286 |
| 17 | 4307974826097 |
| 18 | 25296523200920 |
| 19 | 148448166035239 |
| 20 | 870665283937010 |