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) |
|---|---|
| 2 | 0 |
| 3 | 1 |
| 4 | 13 |
| 5 | 141 |
| 6 | 1456 |
| 7 | 14778 |
| 8 | 149031 |
| 9 | 1499773 |
| 10 | 15089932 |
| 11 | 151927854 |
| 12 | 1531242362 |
| 13 | 15451614738 |
| 14 | 156114597744 |
| 15 | 1579223536788 |
| 16 | 15993825704427 |
| 17 | 162159485143581 |
| 18 | 1645827425223220 |
| 19 | 16720488433727910 |
| 20 | 170023231905932790 |