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 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 17 |
| 5 | 33 |
| 6 | 794 |
| 7 | 2316 |
| 8 | 72354 |
| 9 | 282340 |
| 10 | 10874275 |
| 11 | 53201625 |
| 12 | 2438235715 |
| 13 | 14350108521 |
| 14 | 762963987380 |
| 15 | 5249352196144 |
| 16 | 317685943157892 |
| 17 | 2502137235710736 |
| 18 | 169842891165484965 |
| 19 | 1506994510201252425 |
| 20 | 113394131858832552133 |
| 21 | 1119223325228757961465 |