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 | 1 |
| 1 | 1 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 3 |
| 6 | 3 |
| 7 | 1 |
| 8 | 3 |
| 9 | 15 |
| 10 | 30 |
| 11 | 30 |
| 12 | 27 |
| 13 | 87 |
| 14 | 252 |
| 15 | 420 |
| 16 | 475 |
| 17 | 747 |
| 18 | 2064 |
| 19 | 4632 |
| 20 | 7203 |
| 21 | 9933 |
| 22 | 19635 |
| 23 | 47025 |
| 24 | 92013 |
| 25 | 144745 |
| 26 | 237510 |
| 27 | 498498 |
| 28 | 1073817 |
| 29 | 1969131 |
| 30 | 3267411 |
| 31 | 5977881 |
| 32 | 12462579 |
| 33 | 25035747 |
| 34 | 45090936 |
| 35 | 79414344 |
| 36 | 153115299 |
| 37 | 311198457 |
| 38 | 600883569 |
| 39 | 1090988379 |
| 40 | 2012793705 |