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 | 4095 |
| 2 | 8190 |
| 3 | 16380 |
| 4 | 32760 |
| 5 | 65520 |
| 6 | 131040 |
| 7 | 262080 |
| 8 | 524160 |
| 9 | 1048320 |
| 10 | 2096640 |
| 11 | 4193280 |
| 12 | 8386560 |
| 13 | 16773120 |
| 14 | 16777215 |
| 15 | 33546240 |
| 16 | 33550335 |
| 17 | 33554430 |
| 18 | 67092480 |
| 19 | 67096575 |
| 20 | 67100670 |
| 21 | 67108860 |
| 22 | 134184960 |
| 23 | 134189055 |
| 24 | 134193150 |
| 25 | 134201340 |
| 26 | 134217720 |
| 27 | 268369920 |
| 28 | 268374015 |