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 | 0 |
| 1 | 5 |
| 2 | 30 |
| 3 | 195 |
| 4 | 1220 |
| 5 | 7145 |
| 6 | 40230 |
| 7 | 224175 |
| 8 | 1241000 |
| 9 | 6785325 |
| 10 | 36675650 |
| 11 | 196823495 |
| 12 | 1051855260 |
| 13 | 5599171045 |
| 14 | 29659801150 |
| 15 | 156443274375 |
| 16 | 822605274320 |
| 17 | 4315160956565 |
| 18 | 22584570699690 |
| 19 | 117904543416615 |
| 20 | 614153114242100 |
| 21 | 3193305076085145 |
| 22 | 16578603268278590 |
| 23 | 85946023037719835 |