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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 22 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 110 |
| 10 | 0 |
| 11 | 110 |
| 12 | 330 |
| 13 | 0 |
| 14 | 660 |
| 15 | 924 |
| 16 | 990 |
| 17 | 0 |
| 18 | 0 |
| 19 | 0 |
| 20 | 2662 |
| 21 | 0 |
| 22 | 1980 |
| 23 | 4840 |
| 24 | 0 |
| 25 | 6534 |
| 26 | 7260 |
| 27 | 9460 |
| 28 | 0 |
| 29 | 0 |
| 30 | 0 |
| 31 | 15840 |
| 32 | 0 |
| 33 | 10230 |
| 34 | 21780 |
| 35 | 0 |
| 36 | 27830 |
| 37 | 32670 |
| 38 | 33660 |
| 39 | 0 |
| 40 | 0 |
| 41 | 0 |
| 42 | 50820 |
| 43 | 0 |
| 44 | 30140 |
| 45 | 71236 |
| 46 | 0 |
| 47 | 84700 |
| 48 | 87120 |
| 49 | 99000 |
| 50 | 0 |
| 51 | 0 |
| 52 | 0 |
| 53 | 136840 |
| 54 | 0 |