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 | 1 |
| 2 | 5 |
| 3 | 35 |
| 4 | 900 |
| 5 | 90005 |
| 6 | 43571400 |
| 7 | 95277592625 |
| 8 | 925609100039625 |
| 9 | 40119721052610123750 |
| 10 | 7833164300852979350336250 |
| 11 | 6953552738579427778531249187500 |
| 12 | 28293472829338822230349054996265275000 |
| 13 | 531350037528849507720092485196308155336875000 |