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 | 1 |
| 2 | 8 |
| 3 | 78 |
| 4 | 918 |
| 5 | 12846 |
| 6 | 209616 |
| 7 | 3909228 |
| 8 | 81859548 |
| 9 | 1897344828 |
| 10 | 48135826656 |
| 11 | 1325008302696 |
| 12 | 39292978029768 |
| 13 | 1247949491330088 |
| 14 | 42236558731574208 |
| 15 | 1516738194700667856 |
| 16 | 57573649342673292816 |
| 17 | 2302425590703685075728 |
| 18 | 96720470167595138898048 |