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 | 2 |
| 1 | 20 |
| 2 | 146 |
| 3 | 1028 |
| 4 | 7202 |
| 5 | 50420 |
| 6 | 352946 |
| 7 | 2470628 |
| 8 | 17294402 |
| 9 | 121060820 |
| 10 | 847425746 |
| 11 | 5931980228 |
| 12 | 41523861602 |
| 13 | 290667031220 |
| 14 | 2034669218546 |
| 15 | 14242684529828 |
| 16 | 99698791708802 |
| 17 | 697891541961620 |
| 18 | 4885240793731346 |
| 19 | 34196685556119428 |