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 | 1 |
| 3 | 3 |
| 4 | 11 |
| 5 | 58 |
| 6 | 407 |
| 7 | 4306 |
| 8 | 72489 |
| 9 | 2111013 |
| 10 | 111172234 |
| 11 | 10798144310 |
| 12 | 1944301471861 |
| 13 | 650202565436890 |
| 14 | 404697467417019634 |
| 15 | 470133531223369393920 |
| 16 | 1022561022228933341815171 |
| 17 | 4177761667636803276899047351 |
| 18 | 32163582481439081597751699343141 |
| 19 | 468019937132164016636736323752098741 |