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) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 8 |
| 4 | 58 |
| 5 | 408 |
| 6 | 2859 |
| 7 | 20016 |
| 8 | 140116 |
| 9 | 980816 |
| 10 | 6865717 |
| 11 | 48060024 |
| 12 | 336420174 |
| 13 | 2354941224 |
| 14 | 16484588575 |
| 15 | 115392120032 |
| 16 | 807744840232 |
| 17 | 5654213881632 |
| 18 | 39579497171433 |
| 19 | 277056480200040 |
| 20 | 1939395361400290 |
| 21 | 13575767529802040 |
| 22 | 95030372708614291 |
| 23 | 665212608960300048 |
| 24 | 4656488262722100348 |
| 25 | 32595417839054702448 |