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 | 21 |
| 2 | 441 |
| 3 | 2499 |
| 4 | 14161 |
| 5 | 49861 |
| 6 | 175561 |
| 7 | 475984 |
| 8 | 1290496 |
| 9 | 2958144 |
| 10 | 6780816 |
| 11 | 13816824 |
| 12 | 28153636 |
| 13 | 52561236 |
| 14 | 98128836 |
| 15 | 171205398 |
| 16 | 298702089 |
| 17 | 493723461 |
| 18 | 816073489 |
| 19 | 1290571359 |
| 20 | 2040961329 |
| 21 | 3110933397 |
| 22 | 4741837321 |
| 23 | 7005780418 |
| 24 | 10350620644 |