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 | 10 |
| 4 | 55 |
| 5 | 228 |
| 6 | 801 |
| 7 | 2526 |
| 8 | 7387 |
| 9 | 20440 |
| 10 | 54229 |
| 11 | 139218 |
| 12 | 348111 |
| 13 | 851916 |
| 14 | 2047945 |
| 15 | 4849606 |
| 16 | 11337667 |
| 17 | 26214336 |
| 18 | 60030909 |
| 19 | 136314810 |
| 20 | 307232695 |
| 21 | 687865780 |
| 22 | 1530920881 |
| 23 | 3388997550 |
| 24 | 7465861035 |
| 25 | 16374562728 |
| 26 | 35769024421 |
| 27 | 77846282146 |
| 28 | 168845901727 |