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 | 1 |
| 1 | 6 |
| 2 | 44 |
| 3 | 344 |
| 4 | 2736 |
| 5 | 21856 |
| 6 | 174784 |
| 7 | 1398144 |
| 8 | 11184896 |
| 9 | 89478656 |
| 10 | 715828224 |
| 11 | 5726623744 |
| 12 | 45812985856 |
| 13 | 366503878656 |
| 14 | 2932031012864 |
| 15 | 23456248070144 |
| 16 | 187649984495616 |
| 17 | 1501199875833856 |
| 18 | 12009599006408704 |
| 19 | 96076792050745344 |
| 20 | 768614336404914176 |