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 | 2 |
| 3 | 4 |
| 4 | 6 |
| 5 | 16 |
| 6 | 64 |
| 7 | 1024 |
| 8 | 4096 |
| 9 | 65536 |
| 10 | 262144 |
| 11 | 4194304 |
| 12 | 268435456 |
| 13 | 1073741824 |
| 14 | 68719476736 |
| 15 | 1099511627776 |
| 16 | 4398046511104 |
| 17 | 70368744177664 |
| 18 | 4503599627370496 |
| 19 | 288230376151711744 |
| 20 | 1152921504606846976 |