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 | 1 |
| 2 | 3 |
| 3 | 6 |
| 4 | 15 |
| 5 | 50 |
| 6 | 186 |
| 7 | 834 |
| 8 | 4243 |
| 9 | 24318 |
| 10 | 154780 |
| 11 | 1083952 |
| 12 | 8280624 |
| 13 | 68531308 |
| 14 | 610796150 |
| 15 | 5832677415 |
| 16 | 59411150931 |
| 17 | 642979374958 |
| 18 | 7368000716808 |
| 19 | 89121684577460 |
| 20 | 1134732527849730 |
| 21 | 15170256449030866 |
| 22 | 212469074496520610 |
| 23 | 3111026318662704255 |
| 24 | 47532980801984327584 |