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 | 217 |
| 4 | 530 |
| 5 | 1459 |
| 6 | 3947 |
| 7 | 11306 |
| 8 | 32445 |
| 9 | 96201 |
| 10 | 286920 |
| 11 | 873201 |
| 12 | 2673027 |
| 13 | 8288284 |
| 14 | 25824249 |
| 15 | 81128201 |
| 16 | 255825008 |
| 17 | 811028901 |
| 18 | 2578371055 |
| 19 | 8225731808 |
| 20 | 26296176189 |
| 21 | 84258830581 |
| 22 | 270382678904 |
| 23 | 868986130961 |
| 24 | 2795785995547 |
| 25 | 9004226853968 |