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 | 5 |
| 2 | 31 |
| 3 | 153 |
| 4 | 745 |
| 5 | 3779 |
| 6 | 19011 |
| 7 | 95121 |
| 8 | 475251 |
| 9 | 2375759 |
| 10 | 11880177 |
| 11 | 59406541 |
| 12 | 297033919 |
| 13 | 1485165459 |
| 14 | 7425797777 |
| 15 | 37129022423 |