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 | 4 |
| 3 | 18 |
| 4 | 48 |
| 5 | 150 |
| 6 | 180 |
| 7 | 980 |
| 8 | 2240 |
| 9 | 5670 |
| 10 | 6300 |
| 11 | 30492 |
| 12 | 11088 |
| 13 | 156156 |
| 14 | 168168 |
| 15 | 257400 |
| 16 | 1647360 |
| 17 | 3719430 |
| 18 | 3938220 |
| 19 | 17551820 |
| 20 | 18475600 |
| 21 | 81477396 |
| 22 | 85357272 |
| 23 | 373173528 |
| 24 | 389398464 |
| 25 | 1690097500 |
| 26 | 1757701400 |
| 27 | 7582037400 |
| 28 | 3931426800 |
| 29 | 33738060600 |