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 | 6 |
| 2 | 48 |
| 3 | 408 |
| 4 | 3564 |
| 5 | 31626 |
| 6 | 283548 |
| 7 | 2560872 |
| 8 | 23255964 |
| 9 | 212101176 |
| 10 | 1941110628 |
| 11 | 17815257048 |
| 12 | 163896843300 |
| 13 | 1510891524252 |
| 14 | 13952756564424 |
| 15 | 129048895061208 |
| 16 | 1195191116753436 |
| 17 | 11082661017288264 |
| 18 | 102877353868090080 |
| 19 | 955912961224763232 |
| 20 | 8889969049985302464 |