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 | 3 |
| 2 | 6 |
| 3 | 63 |
| 4 | 264 |
| 5 | 306 |
| 6 | 1914 |
| 7 | 3114 |
| 8 | 31086 |
| 9 | 81813 |
| 10 | 190614 |
| 11 | 251787 |
| 12 | 310956 |
| 13 | 184372811544 |
| 14 | 631933060806 |
| 15 | 3152295978114 |
| 16 | 629836198308687 |
| 17 | 2576231033241456 |
| 18 | 18430047920827535573187 |
| 19 | 31047286456844613647179386 |