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 | 0 |
| 3 | 7 |
| 4 | 105 |
| 5 | 964 |
| 6 | 8005 |
| 7 | 65513 |
| 8 | 538382 |
| 9 | 4468957 |
| 10 | 37588207 |
| 11 | 319972455 |
| 12 | 2753597777 |
| 13 | 23931289984 |
| 14 | 209796541197 |
| 15 | 1853552707266 |
| 16 | 16490531511496 |
| 17 | 147632682729513 |
| 18 | 1329180643501191 |