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 | 5 |
| 3 | 45 |
| 4 | 495 |
| 5 | 6095 |
| 6 | 80617 |
| 7 | 1121075 |
| 8 | 16177405 |
| 9 | 240196280 |
| 10 | 3648115531 |
| 11 | 56440473990 |
| 12 | 886696345225 |
| 13 | 14111836458890 |
| 14 | 227093585071305 |
| 15 | 3689707621144614 |