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 | 39 |
| 4 | 387 |
| 5 | 4516 |
| 6 | 59522 |
| 7 | 864981 |
| 8 | 13641761 |
| 9 | 230931591 |
| 10 | 4162594198 |
| 11 | 79412758356 |
| 12 | 1595971048438 |
| 13 | 33662065586127 |
| 14 | 742852904575909 |
| 15 | 17107642358401929 |
| 16 | 410242691108675077 |
| 17 | 10223836926997402818 |
| 18 | 264339609703677876178 |
| 19 | 7079673476173815446742 |