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 | 4 |
| 2 | 27 |
| 3 | 208 |
| 4 | 1700 |
| 5 | 14364 |
| 6 | 123970 |
| 7 | 1085760 |
| 8 | 9612108 |
| 9 | 85795600 |
| 10 | 770755843 |
| 11 | 6960408624 |
| 12 | 63127818572 |
| 13 | 574609830760 |
| 14 | 5246348656500 |
| 15 | 48027225765120 |
| 16 | 440671237120764 |
| 17 | 4051508174260272 |
| 18 | 37315784743418332 |