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 | 3 |
| 3 | 8 |
| 4 | 24 |
| 5 | 72 |
| 6 | 216 |
| 7 | 648 |
| 8 | 1944 |
| 9 | 5832 |
| 10 | 17496 |
| 11 | 52488 |
| 12 | 157464 |
| 13 | 472392 |
| 14 | 1417176 |
| 15 | 4251528 |
| 16 | 12754584 |
| 17 | 38263752 |
| 18 | 114791256 |
| 19 | 344373768 |
| 20 | 1033121304 |
| 21 | 3099363912 |
| 22 | 9298091736 |
| 23 | 27894275208 |
| 24 | 83682825624 |
| 25 | 251048476872 |
| 26 | 753145430616 |