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) |
|---|---|
| 5 | 9 |
| 6 | 880 |
| 7 | 46150 |
| 8 | 1877925 |
| 9 | 68167144 |
| 10 | 2361060574 |
| 11 | 80937962070 |
| 12 | 2804699592420 |
| 13 | 99488140850125 |
| 14 | 3639765997208250 |
| 15 | 137945128982354064 |
| 16 | 5429115690940281085 |
| 17 | 222153735090644107080 |
| 18 | 9454530091092393873300 |
| 19 | 418429413013429353003828 |
| 20 | 19248239324252460855866832 |