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 | 2 |
| 2 | 5 |
| 3 | 14 |
| 4 | 42 |
| 5 | 143 |
| 6 | 555 |
| 7 | 2485 |
| 8 | 12649 |
| 9 | 72463 |
| 10 | 461207 |
| 11 | 3229622 |
| 12 | 24671899 |
| 13 | 204185616 |
| 14 | 1819837153 |
| 15 | 17378165240 |
| 16 | 177012514388 |
| 17 | 1915724368181 |
| 18 | 21952583954117 |
| 19 | 265533531724484 |
| 20 | 3380877926676504 |
| 21 | 45199008472762756 |