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 | 9 |
| 2 | 81 |
| 3 | 270 |
| 4 | 900 |
| 5 | 2100 |
| 6 | 4900 |
| 7 | 9450 |
| 8 | 18225 |
| 9 | 31185 |
| 10 | 53361 |
| 11 | 84084 |
| 12 | 132496 |
| 13 | 196560 |
| 14 | 291600 |
| 15 | 413100 |
| 16 | 585225 |
| 17 | 799425 |
| 18 | 1092025 |
| 19 | 1448370 |
| 20 | 1920996 |
| 21 | 2486484 |
| 22 | 3218436 |
| 23 | 4081350 |
| 24 | 5175625 |
| 25 | 6449625 |
| 26 | 8037225 |
| 27 | 9865800 |
| 28 | 12110400 |
| 29 | 14671680 |
| 30 | 17774656 |