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 | 7 |
| 2 | 23 |
| 3 | 72 |
| 4 | 218 |
| 5 | 648 |
| 6 | 1907 |
| 7 | 5581 |
| 8 | 16290 |
| 9 | 47502 |
| 10 | 138521 |
| 11 | 404183 |
| 12 | 1180402 |
| 13 | 3450899 |
| 14 | 10099605 |
| 15 | 29589780 |
| 16 | 86781374 |
| 17 | 254761882 |
| 18 | 748580729 |
| 19 | 2201465799 |
| 20 | 6479301022 |
| 21 | 19083705249 |
| 22 | 56246157177 |
| 23 | 165881453558 |
| 24 | 489506759446 |