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 | 20 |
| 3 | 147 |
| 4 | 1143 |
| 5 | 9163 |
| 6 | 74919 |
| 7 | 621015 |
| 8 | 5199909 |
| 9 | 43878315 |
| 10 | 372530781 |
| 11 | 3178551148 |
| 12 | 27231924300 |
| 13 | 234113134518 |
| 14 | 2018601251793 |
| 15 | 17449264269081 |
| 16 | 151169392399773 |