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 | 1 |
| 2 | 63 |
| 3 | 21120 |
| 4 | 20585565 |
| 5 | 44025570225 |
| 6 | 175418438510700 |
| 7 | 1169944052730453000 |
| 8 | 12110024900113702687125 |
| 9 | 183906442861089163922581875 |
| 10 | 3923248989041777334572795737575 |
| 11 | 113570018319217734510803494872644700 |
| 12 | 4337118170117525113961286942555563803500 |