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 | 279 |
| 4 | 1377 |
| 5 | 5895 |
| 6 | 26685 |
| 7 | 118179 |
| 8 | 527913 |
| 9 | 2350215 |
| 10 | 10476981 |
| 11 | 46680363 |
| 12 | 208028817 |
| 13 | 926993439 |
| 14 | 4130894781 |
| 15 | 18407971395 |
| 16 | 82029484089 |
| 17 | 365538508695 |
| 18 | 1628908337349 |
| 19 | 7258719524571 |
| 20 | 32346212936481 |
| 21 | 144140772230991 |