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 | 7 |
| 3 | 26 |
| 4 | 89 |
| 5 | 316 |
| 6 | 1243 |
| 7 | 5564 |
| 8 | 28321 |
| 9 | 162160 |
| 10 | 1032051 |
| 11 | 7226636 |
| 12 | 55206161 |
| 13 | 456886912 |
| 14 | 4072080587 |
| 15 | 38885496092 |
| 16 | 396084390849 |
| 17 | 4286637591872 |
| 18 | 49121248360291 |
| 19 | 594159600856332 |
| 20 | 7565074996215025 |
| 21 | 101137602761945440 |