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 | 1 |
| 2 | 11 |
| 3 | 51 |
| 4 | 192 |
| 5 | 669 |
| 6 | 2222 |
| 7 | 7135 |
| 8 | 22374 |
| 9 | 68916 |
| 10 | 209348 |
| 11 | 628916 |
| 12 | 1872269 |
| 13 | 5531641 |
| 14 | 16238866 |
| 15 | 47410139 |
| 16 | 137758585 |
| 17 | 398617683 |
| 18 | 1149205715 |
| 19 | 3302324374 |
| 20 | 9461757569 |
| 21 | 27038402095 |
| 22 | 77082571383 |
| 23 | 219276117983 |
| 24 | 622541323482 |
| 25 | 1764242459656 |