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) |
|---|---|
| 2 | 1 |
| 3 | 6 |
| 4 | 21 |
| 5 | 30 |
| 6 | 180 |
| 7 | 546 |
| 8 | 140 |
| 9 | 1430 |
| 10 | 6120 |
| 11 | 17710 |
| 12 | 630 |
| 13 | 10920 |
| 14 | 65835 |
| 15 | 245700 |
| 16 | 695640 |
| 17 | 2772 |
| 18 | 81396 |
| 19 | 690690 |
| 20 | 3322704 |
| 21 | 11515140 |
| 22 | 32212719 |
| 23 | 12012 |
| 24 | 596904 |
| 25 | 7125300 |
| 26 | 44170896 |
| 27 | 187336380 |
| 28 | 619851960 |
| 29 | 1721286532 |
| 30 | 51480 |
| 31 | 4326300 |
| 32 | 72624816 |