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 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 31 |
| 4 | 675 |
| 5 | 25231 |
| 6 | 1441923 |
| 7 | 116914351 |
| 8 | 12764590275 |
| 9 | 1805409270031 |
| 10 | 321113303226243 |
| 11 | 70146437009397871 |
| 12 | 18462286083671614275 |
| 13 | 5762225835975165678031 |
| 14 | 2104263061425865873128963 |
| 15 | 888881838896989670838028591 |
| 16 | 430058409024841744606172532675 |