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 | 0 |
| 2 | 3 |
| 3 | 7 |
| 4 | 97 |
| 5 | 811 |
| 6 | 11941 |
| 7 | 178557 |
| 8 | 3354513 |
| 9 | 69809383 |
| 10 | 1659853861 |
| 11 | 43658971753 |
| 12 | 1268252733001 |
| 13 | 40206626846283 |
| 14 | 1383302292511413 |
| 15 | 51308059650256741 |
| 16 | 2041494097105707937 |
| 17 | 86734131445797216847 |
| 18 | 3919172491760452282693 |
| 19 | 187679722656551406628833 |