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 | 4 |
| 1 | 32 |
| 2 | 256 |
| 3 | 2048 |
| 4 | 16384 |
| 5 | 131072 |
| 6 | 1048576 |
| 7 | 8388608 |
| 8 | 67108864 |
| 9 | 536870912 |
| 10 | 4294967296 |
| 11 | 34359738368 |
| 12 | 274877906944 |
| 13 | 2199023255552 |
| 14 | 17592186044416 |
| 15 | 140737488355328 |
| 16 | 1125899906842624 |
| 17 | 9007199254740992 |
| 18 | 72057594037927936 |
| 19 | 576460752303423488 |
| 20 | 4611686018427387904 |