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 | 13 |
| 3 | 409 |
| 4 | 23917 |
| 5 | 2244361 |
| 6 | 308682013 |
| 7 | 58514835289 |
| 8 | 14623910308237 |
| 9 | 4659168491711401 |
| 10 | 1843200116875263613 |
| 11 | 886470355671907534969 |
| 12 | 509366445167037318008557 |
| 13 | 344630301458257894126724041 |
| 14 | 271188703889907190388528763613 |
| 15 | 245570692377888837925941696215449 |