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 | 7 |
| 2 | 54 |
| 3 | 448 |
| 4 | 3896 |
| 5 | 34832 |
| 6 | 316224 |
| 7 | 2894528 |
| 8 | 26609536 |
| 9 | 245174272 |
| 10 | 2261620224 |
| 11 | 20875015168 |
| 12 | 192738922496 |
| 13 | 1779844247552 |
| 14 | 16437306875904 |
| 15 | 151809149370368 |
| 16 | 1402086588645376 |
| 17 | 12949609668739072 |
| 18 | 119602725461950464 |
| 19 | 1104655331042787328 |
| 20 | 10202654714273202176 |