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 | 15 |
| 3 | 125 |
| 4 | 814 |
| 5 | 4641 |
| 6 | 24388 |
| 7 | 121380 |
| 8 | 581400 |
| 9 | 2707386 |
| 10 | 12339569 |
| 11 | 55304535 |
| 12 | 244567050 |
| 13 | 1069784625 |
| 14 | 4637437560 |
| 15 | 19951650840 |
| 16 | 85290143760 |
| 17 | 362608278750 |
| 18 | 1534330716750 |
| 19 | 6465583372794 |
| 20 | 27147098904156 |
| 21 | 113618646478106 |
| 22 | 474177584413720 |
| 23 | 1973918305023000 |
| 24 | 8198353999348240 |