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 | 3 |
| 3 | 14 |
| 4 | 84 |
| 5 | 595 |
| 6 | 4750 |
| 7 | 41541 |
| 8 | 390566 |
| 9 | 3895957 |
| 10 | 40835749 |
| 11 | 446475634 |
| 12 | 5063092427 |
| 13 | 59282989982 |
| 14 | 714081785678 |
| 15 | 8821809194321 |
| 16 | 111497133471808 |
| 17 | 1438600278753167 |
| 18 | 18914553873419637 |
| 19 | 253017056507051876 |
| 20 | 3438813481812082962 |
| 21 | 47430059072002670873 |
| 22 | 663174089700143765780 |