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 | 18 |
| 3 | 159 |
| 4 | 1872 |
| 5 | 27567 |
| 6 | 487152 |
| 7 | 10043163 |
| 8 | 236628864 |
| 9 | 6272181243 |
| 10 | 184725577728 |
| 11 | 5984502588567 |
| 12 | 211503539764224 |
| 13 | 8097842686320423 |
| 14 | 333891770433767424 |
| 15 | 14750451600690993363 |
| 16 | 695078159385543376896 |
| 17 | 34800934548420464971635 |
| 18 | 1844895428525714717343744 |