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 | 2 |
| 1 | 5 |
| 2 | 11 |
| 3 | 19 |
| 4 | 37 |
| 5 | 71 |
| 6 | 137 |
| 7 | 269 |
| 8 | 541 |
| 9 | 1061 |
| 10 | 2087 |
| 11 | 4139 |
| 12 | 8237 |
| 13 | 16433 |
| 14 | 32831 |
| 15 | 65599 |
| 16 | 131143 |
| 17 | 262217 |
| 18 | 524369 |
| 19 | 1048661 |
| 20 | 2097257 |
| 21 | 4194409 |
| 22 | 8388733 |
| 23 | 16777381 |
| 24 | 33554639 |
| 25 | 67109071 |
| 26 | 134217943 |
| 27 | 268435697 |
| 28 | 536871157 |
| 29 | 1073742073 |
| 30 | 2147483929 |