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) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 20 |
| 5 | 220 |
| 6 | 1220 |
| 7 | 2420 |
| 8 | 5060 |
| 9 | 13420 |
| 10 | 14740 |
| 11 | 23620 |
| 12 | 55660 |
| 13 | 145420 |
| 14 | 147620 |
| 15 | 162140 |
| 16 | 237820 |
| 17 | 259820 |
| 18 | 290620 |
| 19 | 308660 |
| 20 | 339020 |
| 21 | 447740 |
| 22 | 847220 |
| 23 | 899140 |
| 24 | 1210220 |
| 25 | 1440820 |
| 26 | 1599620 |
| 27 | 1759340 |
| 28 | 2332660 |
| 29 | 2616020 |
| 30 | 2858020 |
| 31 | 3196820 |
| 32 | 3344660 |