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 | 8 |
| 2 | 48 |
| 3 | 264 |
| 4 | 1408 |
| 5 | 7432 |
| 6 | 39152 |
| 7 | 206600 |
| 8 | 1093760 |
| 9 | 5813000 |
| 10 | 31019568 |
| 11 | 166188552 |
| 12 | 893763840 |
| 13 | 4823997960 |
| 14 | 26124870640 |
| 15 | 141926904328 |
| 16 | 773293020928 |
| 17 | 4224773978632 |
| 18 | 23139861329456 |
| 19 | 127039971696392 |
| 20 | 698993630524032 |
| 21 | 3853860616119048 |
| 22 | 21288789223825648 |