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 | 4 |
| 1 | 15 |
| 2 | 59 |
| 3 | 235 |
| 4 | 939 |
| 5 | 3755 |
| 6 | 15019 |
| 7 | 60075 |
| 8 | 240299 |
| 9 | 961195 |
| 10 | 3844779 |
| 11 | 15379115 |
| 12 | 61516459 |
| 13 | 246065835 |
| 14 | 984263339 |
| 15 | 3937053355 |
| 16 | 15748213419 |
| 17 | 62992853675 |
| 18 | 251971414699 |
| 19 | 1007885658795 |
| 20 | 4031542635179 |
| 21 | 16126170540715 |
| 22 | 64504682162859 |