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 | 66 |
| 2 | 1386 |
| 3 | 16016 |
| 4 | 126126 |
| 5 | 756756 |
| 6 | 3699696 |
| 7 | 15402816 |
| 8 | 56316546 |
| 9 | 184940756 |
| 10 | 554822268 |
| 11 | 1540663488 |
| 12 | 4001445448 |
| 13 | 9802357488 |
| 14 | 22805484768 |
| 15 | 50678855040 |
| 16 | 108088495515 |
| 17 | 222161129190 |
| 18 | 441579528390 |
| 19 | 851355545040 |
| 20 | 1596291646950 |
| 21 | 2917485413700 |
| 22 | 5208073135200 |