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 | 19 |
| 3 | 839 |
| 4 | 6652799 |
| 5 | 1037836799 |
| 6 | 59281238015999 |
| 7 | 20274183401471999 |
| 8 | 4308669456480829439999 |
| 9 | 1473626998956616992423935999999 |
| 10 | 1370473109029653802954260479999999 |