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 | 2 |
| 2 | 5 |
| 3 | 15 |
| 4 | 46 |
| 5 | 139 |
| 6 | 417 |
| 7 | 1250 |
| 8 | 3749 |
| 9 | 11247 |
| 10 | 33742 |
| 11 | 101227 |
| 12 | 303681 |
| 13 | 911042 |
| 14 | 2733125 |
| 15 | 8199375 |
| 16 | 24598126 |
| 17 | 73794379 |
| 18 | 221383137 |
| 19 | 664149410 |
| 20 | 1992448229 |
| 21 | 5977344687 |
| 22 | 17932034062 |
| 23 | 53796102187 |
| 24 | 161388306561 |
| 25 | 484164919682 |
| 26 | 1452494759045 |