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 | 5 |
| 5 | 19 |
| 6 | 67 |
| 7 | 230 |
| 8 | 778 |
| 9 | 2602 |
| 10 | 8618 |
| 11 | 28303 |
| 12 | 92275 |
| 13 | 298949 |
| 14 | 963253 |
| 15 | 3089020 |
| 16 | 9864896 |
| 17 | 31388260 |
| 18 | 99545572 |
| 19 | 314779181 |
| 20 | 992765041 |
| 21 | 3123577735 |
| 22 | 9806581175 |
| 23 | 30727287586 |
| 24 | 96104495110 |
| 25 | 300081382574 |
| 26 | 935547839662 |
| 27 | 2912554595035 |
| 28 | 9055397013503 |
| 29 | 28119390725977 |
| 30 | 87217771234633 |