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 | 2 |
| 1 | 7 |
| 2 | 16 |
| 3 | 32 |
| 4 | 63 |
| 5 | 126 |
| 6 | 254 |
| 7 | 511 |
| 8 | 1024 |
| 9 | 2048 |
| 10 | 4095 |
| 11 | 8190 |
| 12 | 16382 |
| 13 | 32767 |
| 14 | 65536 |
| 15 | 131072 |
| 16 | 262143 |
| 17 | 524286 |
| 18 | 1048574 |
| 19 | 2097151 |
| 20 | 4194304 |
| 21 | 8388608 |
| 22 | 16777215 |
| 23 | 33554430 |
| 24 | 67108862 |
| 25 | 134217727 |
| 26 | 268435456 |
| 27 | 536870912 |
| 28 | 1073741823 |
| 29 | 2147483646 |