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 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 12 |
| 6 | 15 |
| 7 | 27 |
| 8 | 59 |
| 9 | 115 |
| 10 | 127 |
| 11 | 252 |
| 12 | 508 |
| 13 | 1004 |
| 14 | 1021 |
| 15 | 2013 |
| 16 | 2047 |
| 17 | 4031 |
| 18 | 8127 |
| 19 | 16307 |
| 20 | 16375 |
| 21 | 32631 |
| 22 | 32767 |
| 23 | 65279 |
| 24 | 130815 |
| 25 | 261375 |
| 26 | 262143 |
| 27 | 524270 |
| 28 | 1048558 |
| 29 | 2096110 |
| 30 | 2097135 |
| 31 | 4194253 |
| 32 | 4194271 |
| 33 | 8386527 |
| 34 | 8388607 |
| 35 | 16773119 |
| 36 | 33550335 |
| 37 | 67096575 |
| 38 | 67108863 |