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 | 1 |
| 2 | 1 |
| 3 | 5 |
| 4 | 37 |
| 5 | 338 |
| 6 | 3530 |
| 7 | 40546 |
| 8 | 500781 |
| 9 | 6556080 |
| 10 | 90097535 |
| 11 | 1290778689 |
| 12 | 19180015667 |
| 13 | 294460699563 |
| 14 | 4656776745569 |
| 15 | 75682133890995 |
| 16 | 1261603117268148 |
| 17 | 21537605020132685 |
| 18 | 376060923637721700 |
| 19 | 6708681746445946648 |