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 | 0 |
| 2 | 4 |
| 3 | 99 |
| 4 | 16 |
| 5 | 1935 |
| 6 | 64 |
| 7 | 32319 |
| 8 | 256 |
| 9 | 522495 |
| 10 | 1024 |
| 11 | 8381439 |
| 12 | 4096 |
| 13 | 134189055 |
| 14 | 16384 |
| 15 | 2147368959 |
| 16 | 65536 |
| 17 | 34359279615 |
| 18 | 262144 |
| 19 | 549753978879 |
| 20 | 1048576 |
| 21 | 8796085682175 |
| 22 | 4194304 |
| 23 | 140737458995199 |
| 24 | 16777216 |
| 25 | 2251799696244735 |
| 26 | 67108864 |
| 27 | 36028796549201919 |
| 28 | 268435456 |