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 | 76 |
| 2 | 2850 |
| 3 | 70300 |
| 4 | 1282975 |
| 5 | 18474840 |
| 6 | 218618940 |
| 7 | 2186189400 |
| 8 | 18855883575 |
| 9 | 142466675900 |
| 10 | 954526728530 |
| 11 | 5727160371180 |
| 12 | 31022118677225 |
| 13 | 152724276564800 |
| 14 | 687259244541600 |
| 15 | 2840671544105280 |
| 16 | 10830060261901380 |
| 17 | 38223742100828400 |
| 18 | 125288932441604200 |