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 | 7 |
| 3 | 75 |
| 4 | 1033 |
| 5 | 16019 |
| 6 | 269005 |
| 7 | 4767088 |
| 8 | 87914929 |
| 9 | 1671580383 |
| 10 | 32560379840 |
| 11 | 646795901962 |
| 12 | 13058489343812 |
| 13 | 267268692575830 |
| 14 | 5534279506641422 |
| 15 | 115754904055926892 |
| 16 | 2442438538492842691 |
| 17 | 51934447672016653655 |
| 18 | 1111872048730513043539 |
| 19 | 23949840661000275507964 |