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 | 55 |
| 3 | 560 |
| 4 | 5985 |
| 5 | 65780 |
| 6 | 736281 |
| 7 | 8347680 |
| 8 | 95548245 |
| 9 | 1101716330 |
| 10 | 12777711870 |
| 11 | 148902215280 |
| 12 | 1742058970275 |
| 13 | 20448884000160 |
| 14 | 240719591939480 |
| 15 | 2840671544105280 |
| 16 | 33594090947249085 |
| 17 | 398039194165652550 |
| 18 | 4724081931321677925 |
| 19 | 56151322242892212960 |
| 20 | 668324943343021950370 |