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 | 156 |
| 2 | 6162 |
| 3 | 112268 |
| 4 | 1219374 |
| 5 | 9129276 |
| 6 | 51697802 |
| 7 | 235895244 |
| 8 | 907129236 |
| 9 | 3037849828 |
| 10 | 9079799742 |
| 11 | 24680519604 |
| 12 | 61908797418 |
| 13 | 144977296932 |
| 14 | 319917948246 |
| 15 | 670283877588 |
| 16 | 1341750437352 |
| 17 | 2579499722124 |
| 18 | 4783532975546 |
| 19 | 8588601364668 |
| 20 | 14977318285254 |
| 21 | 25437258929836 |