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 | 48 |
| 3 | 64 |
| 4 | 3840 |
| 5 | 1024 |
| 6 | 86016 |
| 7 | 16384 |
| 8 | 983040 |
| 9 | 262144 |
| 10 | 34603008 |
| 11 | 4194304 |
| 12 | 22900899840 |
| 13 | 67108864 |
| 14 | 805306368 |
| 15 | 1073741824 |
| 16 | 1095216660480 |
| 17 | 17179869184 |
| 18 | 27419071217664 |
| 19 | 274877906944 |
| 20 | 181419418583040 |
| 21 | 4398046511104 |