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 | 6 |
| 2 | 62 |
| 3 | 720 |
| 4 | 8806 |
| 5 | 110916 |
| 6 | 1423796 |
| 7 | 18520788 |
| 8 | 243289670 |
| 9 | 3220011684 |
| 10 | 42872967012 |
| 11 | 573608356272 |
| 12 | 7705343534716 |
| 13 | 103857425975400 |
| 14 | 1403902871946000 |
| 15 | 19024773303675420 |
| 16 | 258372666772083270 |
| 17 | 3515644245559211172 |
| 18 | 47918193512409831380 |