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 | 387 |
| 4 | 9904 |
| 5 | 142475 |
| 6 | 850500 |
| 7 | 5287786 |
| 8 | 19400960 |
| 9 | 68736681 |
| 10 | 210682950 |
| 11 | 565317445 |
| 12 | 1328193216 |
| 13 | 3163440917 |
| 14 | 6945663368 |
| 15 | 13045807350 |
| 16 | 26914795520 |
| 17 | 48673795956 |
| 18 | 89900901837 |
| 19 | 149363037975 |
| 20 | 262436871200 |
| 21 | 409003474320 |
| 22 | 711715515852 |
| 23 | 1035199173422 |
| 24 | 1683466675200 |