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 | 1 |
| 2 | 7 |
| 3 | 87 |
| 4 | 3990 |
| 5 | 545544 |
| 6 | 131828470 |
| 7 | 35754455353 |
| 8 | 9300033719253 |
| 9 | 2216652346764139 |
| 10 | 480242932559153642 |
| 11 | 94874768179629903791 |
| 12 | 17193541252761002222476 |
| 13 | 2876019980110265392778268 |