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 | 2 |
| 2 | 22 |
| 3 | 1240 |
| 4 | 316316 |
| 5 | 343855008 |
| 6 | 1551088459936 |
| 7 | 28684932916796288 |
| 8 | 2161788213413182113760 |
| 9 | 661624062463590275090838016 |
| 10 | 820418024446932078541699530057216 |