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 | 7 |
| 2 | 36 |
| 3 | 175 |
| 4 | 841 |
| 5 | 4032 |
| 6 | 19321 |
| 7 | 92575 |
| 8 | 443556 |
| 9 | 2125207 |
| 10 | 10182481 |
| 11 | 48787200 |
| 12 | 233753521 |
| 13 | 1119980407 |
| 14 | 5366148516 |
| 15 | 25710762175 |
| 16 | 123187662361 |
| 17 | 590227549632 |
| 18 | 2827950085801 |
| 19 | 13549522879375 |
| 20 | 64919664311076 |
| 21 | 311048798676007 |
| 22 | 1490324329068961 |
| 23 | 7140572846668800 |