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 | 3 |
| 2 | 7 |
| 3 | 13 |
| 4 | 23 |
| 5 | 41 |
| 6 | 75 |
| 7 | 141 |
| 8 | 271 |
| 9 | 529 |
| 10 | 1043 |
| 11 | 2069 |
| 12 | 4119 |
| 13 | 8217 |
| 14 | 16411 |
| 15 | 32797 |
| 16 | 65567 |
| 17 | 131105 |
| 18 | 262179 |
| 19 | 524325 |
| 20 | 1048615 |
| 21 | 2097193 |
| 22 | 4194347 |
| 23 | 8388653 |
| 24 | 16777263 |
| 25 | 33554481 |
| 26 | 67108915 |
| 27 | 134217781 |
| 28 | 268435511 |
| 29 | 536870969 |
| 30 | 1073741883 |
| 31 | 2147483709 |