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 | 18 |
| 3 | 408 |
| 4 | 2940 |
| 5 | 12600 |
| 6 | 40110 |
| 7 | 105168 |
| 8 | 240408 |
| 9 | 496080 |
| 10 | 945450 |
| 11 | 1690920 |
| 12 | 2870868 |
| 13 | 4667208 |
| 14 | 7313670 |
| 15 | 11104800 |
| 16 | 16405680 |
| 17 | 23662368 |
| 18 | 33413058 |
| 19 | 46299960 |
| 20 | 63081900 |
| 21 | 84647640 |
| 22 | 112029918 |
| 23 | 146420208 |
| 24 | 189184200 |
| 25 | 241878000 |
| 26 | 306265050 |
| 27 | 384333768 |