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 | 4 |
| 5 | 14 |
| 6 | 48 |
| 7 | 151 |
| 8 | 496 |
| 9 | 1679 |
| 10 | 4892 |
| 11 | 16099 |
| 12 | 55566 |
| 13 | 126070 |
| 14 | 437604 |
| 15 | 1610354 |
| 16 | 10586223 |
| 17 | 37753710 |
| 18 | 142615460 |
| 19 | 545804530 |
| 20 | 2501659594 |
| 21 | 9822392246 |
| 22 | 38387432220 |
| 23 | 149904480000 |
| 24 | 622664257407 |
| 25 | 2483093527816 |
| 26 | 9821396841402 |