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 | 0 |
| 5 | 1 |
| 6 | 1 |
| 7 | 7 |
| 8 | 8 |
| 9 | 36 |
| 10 | 45 |
| 11 | 165 |
| 12 | 220 |
| 13 | 715 |
| 14 | 1001 |
| 15 | 3003 |
| 16 | 4368 |
| 17 | 12376 |
| 18 | 18564 |
| 19 | 50388 |
| 20 | 77520 |
| 21 | 203490 |
| 22 | 319770 |
| 23 | 817190 |
| 24 | 1307504 |
| 25 | 3268760 |
| 26 | 5311735 |
| 27 | 13037895 |
| 28 | 21474180 |
| 29 | 51895935 |
| 30 | 86493225 |
| 31 | 206253075 |