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 | 68 |
| 7 | 250 |
| 8 | 935 |
| 9 | 3473 |
| 10 | 12850 |
| 11 | 48066 |
| 12 | 181540 |
| 13 | 686960 |
| 14 | 2600830 |
| 15 | 9893064 |
| 16 | 37819055 |
| 17 | 144917337 |
| 18 | 556011134 |
| 19 | 2138565128 |
| 20 | 8248348136 |
| 21 | 31873293528 |
| 22 | 123320614254 |
| 23 | 477883163716 |
| 24 | 1855021589250 |
| 25 | 7210702449848 |
| 26 | 28058894828756 |