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 | 15 |
| 2 | 56 |
| 3 | 1665 |
| 4 | 3080 |
| 5 | 45375 |
| 6 | 166376 |
| 7 | 9718545 |
| 8 | 8833160 |
| 9 | 127944225 |
| 10 | 461568296 |
| 11 | 13274709555 |
| 12 | 23784791240 |
| 13 | 339933981675 |
| 14 | 1211397511016 |
| 15 | 137818710619425 |
| 16 | 61120313133320 |
| 17 | 865798969339725 |
| 18 | 3061200012378536 |
| 19 | 86466681946098645 |
| 20 | 152460758526595400 |