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) |
|---|---|
| 1 | 0 |
| 2 | 21 |
| 3 | 252 |
| 4 | 1022 |
| 5 | 1589 |
| 6 | 17892 |
| 7 | 21483 |
| 8 | 102837 |
| 9 | 147420 |
| 10 | 213402 |
| 11 | 1445787 |
| 12 | 1707930 |
| 13 | 1711962 |
| 14 | 6589877 |
| 15 | 13667738 |
| 16 | 16092433 |
| 17 | 76545756 |
| 18 | 93093147 |
| 19 | 110132442 |
| 20 | 111443346 |
| 21 | 421817781 |
| 22 | 874802586 |
| 23 | 878996762 |
| 24 | 1029991697 |
| 25 | 1068263553 |