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) |
|---|---|
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 3 |
| 7 | 7 |
| 8 | 14 |
| 9 | 36 |
| 10 | 81 |
| 11 | 221 |
| 12 | 538 |
| 13 | 1530 |
| 14 | 3926 |
| 15 | 11510 |
| 16 | 30694 |
| 17 | 92114 |
| 18 | 252939 |
| 19 | 773259 |
| 20 | 2172830 |
| 21 | 6743122 |
| 22 | 19304190 |
| 23 | 60658606 |
| 24 | 176343390 |
| 25 | 559952824 |
| 26 | 1649008456 |
| 27 | 5283239596 |
| 28 | 15730575554 |
| 29 | 50789908772 |
| 30 | 152663683494 |