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 | 5 |
| 2 | 37 |
| 3 | 235 |
| 4 | 1526 |
| 5 | 9325 |
| 6 | 57255 |
| 7 | 342295 |
| 8 | 2048759 |
| 9 | 12097875 |
| 10 | 71623580 |
| 11 | 421070137 |
| 12 | 2483305077 |
| 13 | 14588495861 |
| 14 | 85996521989 |
| 15 | 505767515227 |
| 16 | 2984447588198 |
| 17 | 17583885515973 |
| 18 | 103920730449567 |
| 19 | 613473612747653 |
| 20 | 3631554358770128 |