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 | 6 |
| 2 | 23 |
| 3 | 72 |
| 4 | 201 |
| 5 | 522 |
| 6 | 1291 |
| 7 | 3084 |
| 8 | 7181 |
| 9 | 16398 |
| 10 | 36879 |
| 11 | 81936 |
| 12 | 180241 |
| 13 | 393234 |
| 14 | 851987 |
| 15 | 1835028 |
| 16 | 3932181 |
| 17 | 8388630 |
| 18 | 17825815 |
| 19 | 37748760 |
| 20 | 79691801 |
| 21 | 167772186 |
| 22 | 352321563 |
| 23 | 738197532 |
| 24 | 1543503901 |
| 25 | 3221225502 |
| 26 | 6710886431 |
| 27 | 13958643744 |