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 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 35 |
| 5 | 924 |
| 6 | 19019 |
| 7 | 14774760 |
| 8 | 767191139 |
| 9 | 2455848787392 |
| 10 | 2993165027255 |
| 11 | 6240848877339043968 |
| 12 | 5018882339663051609 |
| 13 | 238246203631345609763405422080 |