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) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 2 |
| 5 | 8 |
| 6 | 25 |
| 7 | 66 |
| 8 | 159 |
| 9 | 361 |
| 10 | 791 |
| 11 | 1688 |
| 12 | 3539 |
| 13 | 7328 |
| 14 | 15040 |
| 15 | 30669 |
| 16 | 62246 |
| 17 | 125896 |
| 18 | 253975 |
| 19 | 511357 |
| 20 | 1028052 |