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 | 1 |
| 1 | 4 |
| 2 | 12 |
| 3 | 28 |
| 4 | 60 |
| 5 | 124 |
| 6 | 252 |
| 7 | 508 |
| 8 | 1020 |
| 9 | 2044 |
| 10 | 4092 |
| 11 | 8188 |
| 12 | 16380 |
| 13 | 32764 |
| 14 | 65532 |
| 15 | 131068 |
| 16 | 262140 |
| 17 | 524284 |
| 18 | 1048572 |
| 19 | 2097148 |
| 20 | 4194300 |
| 21 | 8388604 |
| 22 | 16777212 |
| 23 | 33554428 |
| 24 | 67108860 |
| 25 | 134217724 |
| 26 | 268435452 |
| 27 | 536870908 |
| 28 | 1073741820 |
| 29 | 2147483644 |
| 30 | 4294967292 |
| 31 | 8589934588 |
| 32 | 17179869180 |