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 | 3 |
| 3 | 6 |
| 4 | 24 |
| 5 | 96 |
| 6 | 396 |
| 7 | 1728 |
| 8 | 7839 |
| 9 | 36438 |
| 10 | 172680 |
| 11 | 831624 |
| 12 | 4058202 |
| 13 | 20021268 |
| 14 | 99697188 |
| 15 | 500429016 |
| 16 | 2529375300 |
| 17 | 12862429920 |
| 18 | 65760468840 |
| 19 | 337817930184 |
| 20 | 1742850773154 |
| 21 | 9026374329108 |
| 22 | 46912014922392 |
| 23 | 244588357460448 |
| 24 | 1278937818954306 |
| 25 | 6705339839722404 |
| 26 | 35241796466506908 |
| 27 | 185643541655678184 |
| 28 | 979972436105339856 |
| 29 | 5183169679909147200 |
| 30 | 27464173024052341200 |