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) |
|---|---|
| 1 | 16 |
| 2 | 70 |
| 3 | 384 |
| 4 | 2534 |
| 5 | 19424 |
| 6 | 169254 |
| 7 | 1650160 |
| 8 | 17784646 |
| 9 | 209855856 |
| 10 | 2689946246 |
| 11 | 37210700576 |
| 12 | 552433526310 |
| 13 | 8759992172224 |
| 14 | 147751562532454 |
| 15 | 2641055171379984 |
| 16 | 49869279287055494 |
| 17 | 991843699479853520 |
| 18 | 20724299315437752006 |
| 19 | 453861919477920665536 |
| 20 | 10395594941305558134886 |