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 | 5 |
| 3 | 41 |
| 4 | 493 |
| 5 | 8161 |
| 6 | 178469 |
| 7 | 4998905 |
| 8 | 174914077 |
| 9 | 7487810257 |
| 10 | 385307632469 |
| 11 | 23477954308841 |
| 12 | 1672313866643917 |
| 13 | 137703723643494721 |
| 14 | 12981787835378567045 |
| 15 | 1389285520249200892889 |
| 16 | 167515121086596348291709 |
| 17 | 22605814306270350503723185 |
| 18 | 3393854148421455726168715445 |