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 | 0 |
| 1 | 1 |
| 2 | 11 |
| 3 | 122 |
| 4 | 1518 |
| 5 | 21423 |
| 6 | 340869 |
| 7 | 6058980 |
| 8 | 119218860 |
| 9 | 2575293165 |
| 10 | 60628447215 |
| 11 | 1545696702270 |
| 12 | 42437227275450 |
| 13 | 1248581232985275 |
| 14 | 39197268410049225 |
| 15 | 1307969571015966600 |
| 16 | 46233376386927067800 |
| 17 | 1725823391345415833625 |
| 18 | 67845041198360981737875 |