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 | 49 |
| 3 | 533 |
| 4 | 6081 |
| 5 | 71365 |
| 6 | 853105 |
| 7 | 10331221 |
| 8 | 126321409 |
| 9 | 1556044805 |
| 10 | 19280812849 |
| 11 | 240054516245 |
| 12 | 3000687934401 |
| 13 | 37634567169477 |
| 14 | 473365023172209 |
| 15 | 5968699720282453 |
| 16 | 75422513665403905 |
| 17 | 954877942305602053 |
| 18 | 12109526474814388273 |
| 19 | 153801537443722913813 |
| 20 | 1956059583033416379841 |