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 | 8 |
| 2 | 64 |
| 3 | 512 |
| 4 | 4096 |
| 5 | 32768 |
| 6 | 262144 |
| 7 | 2097152 |
| 8 | 16777215 |
| 9 | 134217712 |
| 10 | 1073741632 |
| 11 | 8589932544 |
| 12 | 68719456256 |
| 13 | 549755617280 |
| 14 | 4398044676096 |
| 15 | 35184355311616 |
| 16 | 281474825715713 |
| 17 | 2251798471507992 |
| 18 | 18014386698322304 |
| 19 | 144115084996645888 |
| 20 | 1152920611253710848 |
| 21 | 9223364340274069504 |