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 | 0 |
| 2 | 1 |
| 3 | 8 |
| 4 | 15 |
| 5 | 624 |
| 6 | 35 |
| 7 | 117648 |
| 8 | 4095 |
| 9 | 531440 |
| 10 | 9999 |
| 11 | 25937424600 |
| 12 | 20735 |
| 13 | 23298085122480 |
| 14 | 7529535 |
| 15 | 2562890624 |
| 16 | 4294967295 |
| 17 | 48661191875666868480 |
| 18 | 34012223 |
| 19 | 104127350297911241532840 |
| 20 | 25599999999 |
| 21 | 7355827511386640 |
| 22 | 26559922791423 |
| 23 | 907846434775996175406740561328 |
| 24 | 110075314175 |