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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 7 |
| 5 | 47 |
| 6 | 193 |
| 7 | 236 |
| 8 | 1579 |
| 9 | 4195 |
| 10 | 18461 |
| 11 | 62143 |
| 12 | 275781 |
| 13 | 1131909 |
| 14 | 7434169 |
| 15 | 10522660 |
| 16 | 72469339 |
| 17 | 268486155 |
| 18 | 1442237845 |
| 19 | 4284330539 |
| 20 | 18146555293 |
| 21 | 62021099893 |
| 22 | 248289236937 |
| 23 | 798007352239 |
| 24 | 2832660377605 |
| 25 | 11922780595861 |