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 | 16 |
| 4 | 128 |
| 5 | 2048 |
| 6 | 32768 |
| 7 | 262144 |
| 8 | 2097152 |
| 9 | 67108864 |
| 10 | 2147483648 |
| 11 | 17179869184 |
| 12 | 137438953472 |
| 13 | 2199023255552 |
| 14 | 35184372088832 |
| 15 | 281474976710656 |
| 16 | 2251799813685248 |
| 17 | 144115188075855872 |
| 18 | 9223372036854775808 |
| 19 | 73786976294838206464 |
| 20 | 590295810358705651712 |
| 21 | 9444732965739290427392 |