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) |
|---|---|
| 11 | 1 |
| 12 | 11 |
| 13 | 132 |
| 14 | 1430 |
| 15 | 16016 |
| 16 | 183183 |
| 17 | 2170168 |
| 18 | 26682656 |
| 19 | 341093610 |
| 20 | 4535113154 |
| 21 | 62703599816 |
| 22 | 901046882736 |
| 23 | 13446991930372 |
| 24 | 208232533802370 |
| 25 | 3342841274221680 |
| 26 | 55579584231437200 |
| 27 | 956172212838496225 |
| 28 | 17004878491751993700 |
| 29 | 312343867479847052850 |
| 30 | 5920144379977393205640 |