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 | 3 |
| 2 | 10 |
| 3 | 25 |
| 4 | 66 |
| 5 | 154 |
| 6 | 392 |
| 7 | 882 |
| 8 | 2180 |
| 9 | 4796 |
| 10 | 11640 |
| 11 | 25220 |
| 12 | 60424 |
| 13 | 129480 |
| 14 | 307264 |
| 15 | 652936 |
| 16 | 1538064 |
| 17 | 3247024 |
| 18 | 7604000 |
| 19 | 15968400 |
| 20 | 37217312 |
| 21 | 77818016 |
| 22 | 180652416 |
| 23 | 376359200 |
| 24 | 870795328 |
| 25 | 1808574912 |
| 26 | 4172640640 |
| 27 | 8643327040 |