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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 512 |
| 4 | 262144 |
| 5 | 134348544 |
| 6 | 68786454528 |
| 7 | 35218798673920 |
| 8 | 18032024921047040 |
| 9 | 9232396828183582208 |
| 10 | 4726987176064286720000 |
| 11 | 2420217434180064678903808 |
| 12 | 1239151326300193115598749696 |
| 13 | 634445479065716907074042200064 |