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 | 3 |
| 2 | 13 |
| 3 | 49 |
| 4 | 185 |
| 5 | 713 |
| 6 | 2793 |
| 7 | 11049 |
| 8 | 43945 |
| 9 | 175273 |
| 10 | 700073 |
| 11 | 2798249 |
| 12 | 11188905 |
| 13 | 44747433 |
| 14 | 178973353 |
| 15 | 715860649 |
| 16 | 2863377065 |
| 17 | 11453377193 |
| 18 | 45813246633 |
| 19 | 183252462249 |
| 20 | 733008800425 |
| 21 | 2932033104553 |
| 22 | 11728128223913 |
| 23 | 46912504507049 |
| 24 | 187650001250985 |
| 25 | 750599971449513 |
| 26 | 3002399818689193 |
| 27 | 12009599140539049 |