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 | 12 |
| 2 | 40 |
| 3 | 220 |
| 4 | 768 |
| 5 | 14808 |
| 6 | 51700 |
| 7 | 285520 |
| 8 | 996852 |
| 9 | 19220772 |
| 10 | 67106560 |
| 11 | 370604740 |
| 12 | 1293913128 |
| 13 | 24948547248 |
| 14 | 87104263180 |
| 15 | 481044667000 |
| 16 | 1679498243292 |
| 17 | 32383195107132 |
| 18 | 113061266501080 |
| 19 | 624395607161260 |
| 20 | 2179987425879888 |
| 21 | 42033362300510088 |
| 22 | 146753436814138660 |