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 | 2047 |
| 2 | 8388607 |
| 3 | 1082401 |
| 4 | 3277 |
| 5 | 536870911 |
| 6 | 8727391 |
| 7 | 4033 |
| 8 | 137438953471 |
| 9 | 9588151 |
| 10 | 2199023255551 |
| 11 | 8796093022207 |
| 12 | 838861 |
| 13 | 14709241 |
| 14 | 140737488355327 |
| 15 | 65281 |
| 16 | 1016801 |
| 17 | 2454285751 |
| 18 | 13421773 |
| 19 | 9007199254740991 |
| 20 | 567767102431 |
| 21 | 39268347319 |
| 22 | 178956971 |
| 23 | 576460752303423487 |
| 24 | 80581 |