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 | 2 |
| 2 | 25 |
| 3 | 1300 |
| 4 | 666536 |
| 5 | 1866588100 |
| 6 | 40227366213200 |
| 7 | 5615962423683300000 |
| 8 | 5515452582144085933300000 |
| 9 | 36695607554641784976763692852800 |
| 10 | 1681984849693348507666402129737211600000 |