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 | 1 |
| 3 | 14 |
| 4 | 159 |
| 5 | 1680 |
| 6 | 17147 |
| 7 | 171612 |
| 8 | 1696491 |
| 9 | 16631840 |
| 10 | 162090756 |
| 11 | 1572801142 |
| 12 | 15210259585 |
| 13 | 146710561296 |
| 14 | 1412132981778 |
| 15 | 13569013500024 |
| 16 | 130199055578307 |
| 17 | 1247825314752768 |
| 18 | 11947157409479180 |
| 19 | 114288613130155608 |
| 20 | 1092495810452593564 |
| 21 | 10436544808441964352 |