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 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 23 |
| 6 | 53 |
| 7 | 115 |
| 8 | 241 |
| 9 | 495 |
| 10 | 1005 |
| 11 | 2027 |
| 12 | 4073 |
| 13 | 8167 |
| 14 | 16357 |
| 15 | 32739 |
| 16 | 65505 |
| 17 | 131039 |
| 18 | 262109 |
| 19 | 524251 |
| 20 | 1048537 |
| 21 | 2097111 |
| 22 | 4194261 |
| 23 | 8388563 |
| 24 | 16777169 |