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 | 5 |
| 2 | 66 |
| 3 | 680 |
| 4 | 2576 |
| 5 | 33408 |
| 6 | 14080 |
| 7 | 545792 |
| 8 | 481280 |
| 9 | 29523968 |
| 10 | 73465856 |
| 11 | 27525120 |
| 12 | 856162304 |
| 13 | 1153433600 |
| 14 | 18798870528 |
| 15 | 86603988992 |
| 16 | 2080374784 |
| 17 | 2385854332928 |
| 18 | 3216930504704 |
| 19 | 71829033058304 |
| 20 | 7593502179328 |
| 21 | 281749854617600 |