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 | 34 |
| 4 | 307 |
| 5 | 3456 |
| 6 | 46659 |
| 7 | 734882 |
| 8 | 13227995 |
| 9 | 267871036 |
| 10 | 6027206803 |
| 11 | 149176155030 |
| 12 | 4027831914099 |
| 13 | 117816299188472 |
| 14 | 3711283196035523 |
| 15 | 125258162280991858 |
| 16 | 4509378597919760779 |
| 17 | 172486973301491042964 |
| 18 | 6985853719202139488211 |
| 19 | 298650859698906574479278 |