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 | 5 |
| 2 | 1805 |
| 3 | 508805 |
| 4 | 140503005 |
| 5 | 38720000000 |
| 6 | 10668237057005 |
| 7 | 2939274449134805 |
| 8 | 809816405722655805 |
| 9 | 223117116976138566005 |
| 10 | 61472262298219520000000 |
| 11 | 16936571572967914651674005 |
| 12 | 4666290873812984282155907805 |
| 13 | 1285636259054921313298518442805 |