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 | 8 |
| 4 | 80 |
| 5 | 1568 |
| 6 | 42308 |
| 7 | 1632544 |
| 8 | 82377984 |
| 9 | 5340729728 |
| 10 | 429905599744 |
| 11 | 42164608801024 |
| 12 | 4944386388782080 |
| 13 | 683353973472423936 |
| 14 | 109907353260811403520 |
| 15 | 20352830852731108528128 |
| 16 | 4299139435513999926820864 |
| 17 | 1027450150728092835655335936 |
| 18 | 275824741022588671077713641472 |