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 | 12 |
| 2 | 144 |
| 3 | 396 |
| 4 | 1089 |
| 5 | 6765 |
| 6 | 42025 |
| 7 | 157440 |
| 8 | 589824 |
| 9 | 3005184 |
| 10 | 15311569 |
| 11 | 64177113 |
| 12 | 268992801 |
| 13 | 1274751324 |
| 14 | 6041020176 |
| 15 | 26465410620 |
| 16 | 115943655025 |
| 17 | 534003435845 |
| 18 | 2459467656361 |
| 19 | 10969953831936 |
| 20 | 48929241563136 |
| 21 | 222765694221312 |