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) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 56 |
| 5 | 289 |
| 6 | 1529 |
| 7 | 8152 |
| 8 | 43676 |
| 9 | 234707 |
| 10 | 1264018 |
| 11 | 6818793 |
| 12 | 36833925 |
| 13 | 199192142 |
| 14 | 1078202540 |
| 15 | 5840738361 |
| 16 | 31660718262 |
| 17 | 171717441011 |
| 18 | 931774434881 |
| 19 | 5057989479520 |
| 20 | 27465580937300 |
| 21 | 149183431937487 |
| 22 | 810502022734382 |