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 | 0 |
| 1 | 8 |
| 2 | 56 |
| 3 | 392 |
| 4 | 3080 |
| 5 | 24248 |
| 6 | 193592 |
| 7 | 1545656 |
| 8 | 12362168 |
| 9 | 98873096 |
| 10 | 790960520 |
| 11 | 6327490568 |
| 12 | 50619730952 |
| 13 | 404956301960 |
| 14 | 3239648870024 |
| 15 | 25917178598024 |
| 16 | 207337416422024 |
| 17 | 1658699232503096 |
| 18 | 13269593761151672 |
| 19 | 106156749298252856 |
| 20 | 849253993595062328 |
| 21 | 6794031942433008056 |