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 | 1 |
| 2 | 0 |
| 3 | 3 |
| 4 | 0 |
| 5 | 0 |
| 6 | 6 |
| 7 | 0 |
| 8 | 0 |
| 9 | 36 |
| 10 | 28 |
| 11 | 0 |
| 12 | 66 |
| 13 | 0 |
| 14 | 0 |
| 15 | 78 |
| 16 | 0 |
| 17 | 0 |
| 18 | 378 |
| 19 | 496 |
| 20 | 0 |
| 21 | 1596 |
| 22 | 0 |
| 23 | 0 |
| 24 | 8385 |
| 25 | 0 |
| 26 | 0 |
| 27 | 5778 |
| 28 | 5995 |
| 29 | 0 |
| 30 | 8778 |
| 31 | 0 |
| 32 | 0 |
| 33 | 47895 |
| 34 | 0 |
| 35 | 0 |
| 36 | 67896 |
| 37 | 58996 |
| 38 | 0 |
| 39 | 196878 |
| 40 | 0 |
| 41 | 0 |
| 42 | 468996 |
| 43 | 0 |
| 44 | 0 |
| 45 | 887778 |
| 46 | 1788886 |
| 47 | 0 |
| 48 | 4896885 |
| 49 | 0 |
| 50 | 0 |
| 51 | 5897895 |
| 52 | 0 |
| 53 | 0 |
| 54 | 13999986 |
| 55 | 15997996 |
| 56 | 0 |
| 57 | 38997696 |