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 | 0 |
| 2 | 12 |
| 3 | 113 |
| 4 | 820 |
| 5 | 5773 |
| 6 | 41620 |
| 7 | 305641 |
| 8 | 2274080 |
| 9 | 17114289 |
| 10 | 129576988 |
| 11 | 987231526 |
| 12 | 7551235806 |
| 13 | 57992581744 |
| 14 | 446683948074 |
| 15 | 3450295188177 |
| 16 | 26710836161850 |
| 17 | 207217760171898 |
| 18 | 1610393410029550 |
| 19 | 12535446041119817 |
| 20 | 97715224210141008 |