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 | 0 |
| 1 | 16777216 |
| 2 | 4294967296 |
| 3 | 110075314176 |
| 4 | 1099511627776 |
| 5 | 6553600000000 |
| 6 | 28179280429056 |
| 7 | 96717311574016 |
| 8 | 281474976710656 |
| 9 | 722204136308736 |
| 10 | 1677721600000000 |
| 11 | 3596345248055296 |
| 12 | 7213895789838336 |
| 13 | 13685690504052736 |