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 | 61 |
| 3 | 301 |
| 4 | 353 |
| 5 | 1307 |
| 6 | 4505 |
| 7 | 16265 |
| 8 | 46773 |
| 9 | 136935 |
| 10 | 481479 |
| 11 | 1631059 |
| 12 | 5055540 |
| 13 | 16067446 |
| 14 | 52668892 |
| 15 | 175365361 |
| 16 | 562163896 |
| 17 | 1807393316 |
| 18 | 5893267465 |
| 19 | 19311336692 |
| 20 | 62623833763 |
| 21 | 202770902304 |
| 22 | 659588139794 |
| 23 | 2152022230238 |
| 24 | 6997053941406 |