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 | 4 |
| 2 | 42 |
| 3 | 499 |
| 4 | 6250 |
| 5 | 80634 |
| 6 | 1060269 |
| 7 | 14127852 |
| 8 | 190102482 |
| 9 | 2577310285 |
| 10 | 35150819132 |
| 11 | 481734467955 |
| 12 | 6628611532621 |
| 13 | 91517611501008 |
| 14 | 1267182734325900 |
| 15 | 17589579427715124 |
| 16 | 244689432718144770 |
| 17 | 3410399867585709501 |
| 18 | 47613678409439712861 |
| 19 | 665756829352248572725 |