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 | 2 |
| 2 | 4 |
| 3 | 8 |
| 4 | 32 |
| 5 | 128 |
| 6 | 512 |
| 7 | 4096 |
| 8 | 32768 |
| 9 | 262144 |
| 10 | 4194304 |
| 11 | 67108864 |
| 12 | 1073741824 |
| 13 | 34359738368 |
| 14 | 1099511627776 |
| 15 | 35184372088832 |
| 16 | 2251799813685248 |
| 17 | 144115188075855872 |
| 18 | 9223372036854775808 |
| 19 | 1180591620717411303424 |
| 20 | 151115727451828646838272 |