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 | 8 |
| 2 | 28 |
| 3 | 168 |
| 4 | 1008 |
| 5 | 6552 |
| 6 | 43596 |
| 7 | 299592 |
| 8 | 2096640 |
| 9 | 14913024 |
| 10 | 107370900 |
| 11 | 780903144 |
| 12 | 5726600880 |
| 13 | 42288908760 |
| 14 | 314146029564 |
| 15 | 2345624803704 |
| 16 | 17592184995840 |
| 17 | 132458812569720 |
| 18 | 1000799909722368 |
| 19 | 7585009898729256 |