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 | 945 |
| 1 | 6 |
| 2 | 20 |
| 3 | 88 |
| 4 | 272 |
| 5 | 1184 |
| 6 | 4288 |
| 7 | 16768 |
| 8 | 65792 |
| 9 | 266752 |
| 10 | 1055744 |
| 11 | 4204544 |
| 12 | 16789504 |
| 13 | 67248128 |
| 14 | 268877824 |
| 15 | 1073840128 |
| 16 | 4295032832 |
| 17 | 17183670272 |
| 18 | 68720263168 |
| 19 | 274888916992 |
| 20 | 1099518967808 |
| 21 | 4398082162688 |
| 22 | 17592248958976 |