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 | 1 |
| 2 | 10 |
| 3 | 150 |
| 4 | 2625 |
| 5 | 49875 |
| 6 | 997500 |
| 7 | 20662500 |
| 8 | 439078125 |
| 9 | 9513359375 |
| 10 | 209293906250 |
| 11 | 4661546093750 |
| 12 | 104884787109375 |
| 13 | 2380077861328125 |
| 14 | 54401779687500000 |
| 15 | 1251240932812500000 |
| 16 | 28934946571289062500 |
| 17 | 672311993862304687500 |
| 18 | 15687279856787109375000 |
| 19 | 367412607172119140625000 |