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 | 5 |
| 2 | 28 |
| 3 | 170 |
| 4 | 1084 |
| 5 | 7100 |
| 6 | 47152 |
| 7 | 315320 |
| 8 | 2115856 |
| 9 | 14221520 |
| 10 | 95666368 |
| 11 | 643790240 |
| 12 | 4333242304 |
| 13 | 29169037760 |
| 14 | 196359046912 |
| 15 | 1321871638400 |
| 16 | 8898817351936 |
| 17 | 59906997474560 |
| 18 | 403295993003008 |
| 19 | 2715005985589760 |
| 20 | 18277548009831424 |