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 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 39 |
| 5 | 23988 |
| 6 | 2685 |
| 7 | 1079830 |
| 8 | 3 |
| 9 | 1798749736 |
| 10 | 7936950713 |
| 11 | 314244766442 |
| 12 | 895397198495 |
| 13 | 65283613526364 |
| 14 | 203550894972341 |
| 15 | 27025091041430142 |
| 16 | 54487836217255419 |
| 17 | 2756442714229679952 |
| 18 | 34856858877609547377 |
| 19 | 2262552012902592868562 |
| 20 | 4616799241038411627031 |
| 21 | 4 |
| 22 | 116433218705414728492013 |