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 | 12 |
| 2 | 144 |
| 3 | 1750 |
| 4 | 23420 |
| 5 | 303240 |
| 6 | 3641100 |
| 7 | 46113200 |
| 8 | 575360400 |
| 9 | 7346545000 |
| 10 | 112402762000 |
| 11 | 1351035564000 |
| 12 | 16432451210000 |
| 13 | 221411634520000 |
| 14 | 2657142036440000 |
| 15 | 34327724461500000 |
| 16 | 434157115760200000 |
| 17 | 5432127413542400000 |
| 18 | 67405553164731000000 |
| 19 | 1053071060221172000000 |