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 | 3 |
| 2 | 24 |
| 3 | 282 |
| 4 | 4236 |
| 5 | 76548 |
| 6 | 1608864 |
| 7 | 38488152 |
| 8 | 1032125136 |
| 9 | 30670171248 |
| 10 | 1000637672064 |
| 11 | 35571839009952 |
| 12 | 1368990872569536 |
| 13 | 56720594992438848 |
| 14 | 2517761078627172864 |
| 15 | 119222916630934484352 |
| 16 | 5999613754698100628736 |
| 17 | 319763269764299852744448 |
| 18 | 17994913747767982690289664 |