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 | 0 |
| 1 | 1 |
| 2 | 8 |
| 3 | 54 |
| 4 | 320 |
| 5 | 1750 |
| 6 | 9072 |
| 7 | 45276 |
| 8 | 219648 |
| 9 | 1042470 |
| 10 | 4862000 |
| 11 | 22355476 |
| 12 | 101582208 |
| 13 | 457002364 |
| 14 | 2038517600 |
| 15 | 9026235000 |
| 16 | 39710085120 |
| 17 | 173712232710 |
| 18 | 756088415280 |
| 19 | 3276123843300 |
| 20 | 14138105520000 |
| 21 | 60790319209620 |
| 22 | 260516811228960 |
| 23 | 1113068351807880 |
| 24 | 4742456099097600 |
| 25 | 20154752301937500 |
| 26 | 85453569951920352 |