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) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 18 |
| 5 | 50 |
| 6 | 132 |
| 7 | 351 |
| 8 | 924 |
| 9 | 2431 |
| 10 | 6380 |
| 11 | 16732 |
| 12 | 43848 |
| 13 | 114869 |
| 14 | 300846 |
| 15 | 787815 |
| 16 | 2062830 |
| 17 | 5401054 |
| 18 | 14140940 |
| 19 | 37022755 |
| 20 | 96928920 |
| 21 | 253766591 |
| 22 | 664375032 |
| 23 | 1739365272 |
| 24 | 4553731728 |
| 25 | 11921847625 |
| 26 | 31211839802 |
| 27 | 81713718151 |
| 28 | 213929389674 |