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) |
|---|---|
| 0 | 1 |
| 1 | 9 |
| 2 | 67 |
| 3 | 458 |
| 4 | 2979 |
| 5 | 18750 |
| 6 | 115278 |
| 7 | 696372 |
| 8 | 4149283 |
| 9 | 24452534 |
| 10 | 142808922 |
| 11 | 827780684 |
| 12 | 4767638158 |
| 13 | 27309438252 |
| 14 | 155689424316 |
| 15 | 883891633896 |
| 16 | 4999703023395 |
| 17 | 28188457323366 |
| 18 | 158463492162594 |
| 19 | 888473780483292 |
| 20 | 4969653746436762 |
| 21 | 27737520941131140 |
| 22 | 154507945286680452 |