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 | 2 |
| 3 | 9 |
| 4 | 83 |
| 5 | 1391 |
| 6 | 38498 |
| 7 | 1638505 |
| 8 | 101604805 |
| 9 | 8802059341 |
| 10 | 1030071680506 |
| 11 | 158430831805049 |
| 12 | 31302182958422223 |
| 13 | 7792558134438194339 |
| 14 | 2404183465743291972650 |
| 15 | 906172339589098358635601 |
| 16 | 412063269903446575653003241 |
| 17 | 223575203315439598127658946681 |
| 18 | 143324925086774266814499800353234 |