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 | 1 |
| 3 | 7 |
| 4 | 25 |
| 5 | 141 |
| 6 | 1171 |
| 7 | 9913 |
| 8 | 85233 |
| 9 | 907273 |
| 10 | 11010691 |
| 11 | 143824341 |
| 12 | 1988010553 |
| 13 | 29605763773 |
| 14 | 475664908083 |
| 15 | 8284952367721 |
| 16 | 153508912353121 |
| 17 | 2997209814190353 |
| 18 | 61485486404453443 |
| 19 | 1326994255131585373 |
| 20 | 30144049509450774441 |
| 21 | 718905298680190094341 |
| 22 | 17940822818538396541843 |