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 | 4 |
| 2 | 36 |
| 3 | 560 |
| 4 | 17550 |
| 5 | 1370754 |
| 6 | 324540216 |
| 7 | 267212177232 |
| 8 | 822871715492970 |
| 9 | 9728874233306696390 |
| 10 | 442491588454024774291770 |
| 11 | 76919746769405407508866898400 |
| 12 | 50743487119356450255156023756871000 |