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 | 1 |
| 2 | 1 |
| 3 | 7 |
| 4 | 28 |
| 5 | 76 |
| 6 | 256 |
| 7 | 1072 |
| 8 | 4288 |
| 9 | 16576 |
| 10 | 65536 |
| 11 | 262912 |
| 12 | 1051648 |
| 13 | 4197376 |
| 14 | 16777216 |
| 15 | 67121152 |
| 16 | 268484608 |
| 17 | 1073790976 |
| 18 | 4294967296 |
| 19 | 17180065792 |
| 20 | 68720263168 |
| 21 | 274878693376 |
| 22 | 1099511627776 |
| 23 | 4398049656832 |
| 24 | 17592198627328 |
| 25 | 70368756760576 |
| 26 | 281474976710656 |
| 27 | 1125899957174272 |
| 28 | 4503599828697088 |
| 29 | 18014398710808576 |