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 | 1 |
| 3 | 9 |
| 4 | 81 |
| 5 | 225 |
| 6 | 1369 |
| 7 | 2209 |
| 8 | 13689 |
| 9 | 106929 |
| 10 | 915849 |
| 11 | 8105409 |
| 12 | 72539289 |
| 13 | 651627729 |
| 14 | 1097530641 |
| 15 | 1108290681 |
| 16 | 2176502409 |
| 17 | 4469591025 |
| 18 | 21803770921 |
| 19 | 26143332721 |
| 20 | 47825753481 |
| 21 | 253493117361 |
| 22 | 396488086929 |
| 23 | 845198906409 |
| 24 | 4313600840241 |
| 25 | 9044785577025 |
| 26 | 50417568884089 |
| 27 | 62908961921289 |