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 | 2 |
| 3 | 3 |
| 4 | 8 |
| 5 | 26 |
| 6 | 107 |
| 7 | 492 |
| 8 | 2481 |
| 9 | 13599 |
| 10 | 81288 |
| 11 | 531343 |
| 12 | 3790344 |
| 13 | 29279668 |
| 14 | 242278645 |
| 15 | 2125160800 |
| 16 | 19608039385 |
| 17 | 189437263949 |
| 18 | 1912477987102 |
| 19 | 20161911603747 |
| 20 | 221869317899264 |
| 21 | 2546362514225134 |
| 22 | 30430660439311103 |