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 | 6 |
| 3 | 50 |
| 4 | 392 |
| 5 | 2970 |
| 6 | 22022 |
| 7 | 160888 |
| 8 | 1162800 |
| 9 | 8335338 |
| 10 | 59366450 |
| 11 | 420630210 |
| 12 | 2967563040 |
| 13 | 20861295000 |
| 14 | 146203657992 |
| 15 | 1021964428880 |
| 16 | 7127260128736 |
| 17 | 49606676100234 |
| 18 | 344658278690250 |
| 19 | 2390849931605590 |
| 20 | 16561583202364200 |
| 21 | 114577083158683530 |
| 22 | 791757148201073670 |