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 | 2 |
| 2 | 3 |
| 3 | 15 |
| 4 | 121 |
| 5 | 3906 |
| 6 | 299593 |
| 7 | 67977560 |
| 8 | 39714002329 |
| 9 | 62556901638175 |
| 10 | 257985813269495081 |
| 11 | 2806709131423433412540 |
| 12 | 80052769211806164721787281 |
| 13 | 5990939163682951316587217125254 |
| 14 | 1174714712853607653027182667701045767 |
| 15 | 603476089599958368340121395090311986863711 |