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 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 12 |
| 5 | 57 |
| 6 | 216 |
| 7 | 741 |
| 8 | 2412 |
| 9 | 7617 |
| 10 | 23616 |
| 11 | 72381 |
| 12 | 220212 |
| 13 | 666777 |
| 14 | 2012616 |
| 15 | 6062421 |
| 16 | 18236412 |
| 17 | 54807537 |
| 18 | 164619216 |
| 19 | 494250861 |
| 20 | 1483539012 |
| 21 | 4452189897 |
| 22 | 13359715416 |
| 23 | 40085437701 |
| 24 | 120268896012 |
| 25 | 360831853857 |
| 26 | 1082545893216 |