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 | 11 |
| 2 | 142 |
| 3 | 2086 |
| 4 | 34184 |
| 5 | 616120 |
| 6 | 12083920 |
| 7 | 255749840 |
| 8 | 5801633920 |
| 9 | 140276126080 |
| 10 | 3598075308800 |
| 11 | 97512721964800 |
| 12 | 2782552712473600 |
| 13 | 83347512973644800 |
| 14 | 2613606571616819200 |
| 15 | 85594543750221568000 |
| 16 | 2921314815145299968000 |
| 17 | 103704333851191177216000 |