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 | 2 |
| 3 | 5 |
| 4 | 15 |
| 5 | 49 |
| 6 | 173 |
| 7 | 639 |
| 8 | 2469 |
| 9 | 9997 |
| 10 | 43109 |
| 11 | 205092 |
| 12 | 1153646 |
| 13 | 8523086 |
| 14 | 91156133 |
| 15 | 1446766659 |
| 16 | 32998508358 |
| 17 | 1047766596136 |
| 18 | 45632564217917 |
| 19 | 2711308588849394 |
| 20 | 219364550983697100 |
| 21 | 24151476334929009951 |
| 22 | 3618445112608409433287 |