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 | 2 |
| 5 | 5 |
| 6 | 17 |
| 7 | 68 |
| 8 | 267 |
| 9 | 1230 |
| 10 | 5564 |
| 11 | 27575 |
| 12 | 136644 |
| 13 | 714772 |
| 14 | 3743265 |
| 15 | 20353789 |
| 16 | 110723361 |
| 17 | 619347223 |
| 18 | 3464770044 |
| 19 | 19801412122 |
| 20 | 113178582936 |