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 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 4 |
| 5 | 7 |
| 6 | 22 |
| 7 | 49 |
| 8 | 143 |
| 9 | 359 |
| 10 | 1025 |
| 11 | 2742 |
| 12 | 7812 |
| 13 | 21666 |
| 14 | 62044 |
| 15 | 175927 |
| 16 | 507484 |
| 17 | 1460297 |
| 18 | 4243802 |
| 19 | 12340559 |
| 20 | 36108354 |
| 21 | 105839241 |
| 22 | 311551092 |
| 23 | 919000678 |
| 24 | 2719362502 |
| 25 | 8063263402 |
| 26 | 23967845874 |
| 27 | 71379427920 |
| 28 | 213010634136 |
| 29 | 636757780808 |
| 30 | 1906765570820 |