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 | 18 |
| 4 | 412 |
| 5 | 4436 |
| 6 | 26133 |
| 7 | 111066 |
| 8 | 376560 |
| 9 | 1080942 |
| 10 | 2732909 |
| 11 | 6253408 |
| 12 | 13204356 |
| 13 | 26100160 |
| 14 | 48819677 |
| 15 | 87137934 |
| 16 | 149398608 |
| 17 | 247349946 |
| 18 | 397168485 |
| 19 | 620696612 |
| 20 | 946921684 |
| 21 | 1413726108 |
| 22 | 2069939461 |
| 23 | 2977725410 |
| 24 | 4215337872 |