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 | 6 |
| 3 | 30 |
| 4 | 270 |
| 5 | 4830 |
| 6 | 189630 |
| 7 | 16912350 |
| 8 | 3353412510 |
| 9 | 1432516194270 |
| 10 | 1288072947428190 |
| 11 | 2400557459496515550 |
| 12 | 9177479849690707865310 |
| 13 | 71463760915341917360748510 |
| 14 | 1127799535042492118475108550110 |