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 | 3 |
| 2 | 91 |
| 3 | 276 |
| 4 | 8371 |
| 5 | 25389 |
| 6 | 770041 |
| 7 | 2335512 |
| 8 | 70835401 |
| 9 | 214841715 |
| 10 | 6516086851 |
| 11 | 19763102268 |
| 12 | 599409154891 |
| 13 | 1817990566941 |
| 14 | 55139126163121 |
| 15 | 167235369056304 |
| 16 | 5072200197852241 |
| 17 | 15383835962613027 |
| 18 | 466587279076243051 |
| 19 | 1415145673191342180 |
| 20 | 42920957474816508451 |