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 | 4 |
| 2 | 32 |
| 3 | 128 |
| 4 | 2048 |
| 5 | 8192 |
| 6 | 65536 |
| 7 | 262144 |
| 8 | 8388608 |
| 9 | 33554432 |
| 10 | 268435456 |
| 11 | 1073741824 |
| 12 | 17179869184 |
| 13 | 68719476736 |
| 14 | 549755813888 |
| 15 | 2199023255552 |
| 16 | 140737488355328 |
| 17 | 562949953421312 |
| 18 | 4503599627370496 |
| 19 | 18014398509481984 |
| 20 | 288230376151711744 |
| 21 | 1152921504606846976 |