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 | 9 |
| 2 | 81 |
| 3 | 297 |
| 4 | 1004 |
| 5 | 2942 |
| 6 | 7305 |
| 7 | 17911 |
| 8 | 40262 |
| 9 | 87990 |
| 10 | 187012 |
| 11 | 385400 |
| 12 | 783726 |
| 13 | 1564402 |
| 14 | 3084097 |
| 15 | 6019187 |
| 16 | 11629307 |
| 17 | 22307563 |
| 18 | 42493220 |
| 19 | 80468378 |
| 20 | 151622295 |
| 21 | 284370183 |
| 22 | 531240776 |
| 23 | 988874960 |
| 24 | 1834816342 |
| 25 | 3394683936 |
| 26 | 6264203818 |
| 27 | 11531988896 |