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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 4 |
| 5 | 11 |
| 6 | 36 |
| 7 | 95 |
| 8 | 257 |
| 9 | 685 |
| 10 | 1747 |
| 11 | 4405 |
| 12 | 10601 |
| 13 | 25991 |
| 14 | 63589 |
| 15 | 156965 |
| 16 | 387971 |
| 17 | 973753 |
| 18 | 2471133 |
| 19 | 6340799 |