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 | 6 |
| 4 | 405 |
| 5 | 5024 |
| 6 | 31320 |
| 7 | 133544 |
| 8 | 446421 |
| 9 | 1258590 |
| 10 | 3126724 |
| 11 | 7042930 |
| 12 | 14669709 |
| 13 | 28658436 |
| 14 | 53069000 |
| 15 | 93909924 |
| 16 | 159819965 |
| 17 | 262913874 |
| 18 | 419816676 |
| 19 | 652912510 |
| 20 | 991835749 |
| 21 | 1475233800 |
| 22 | 2152832664 |
| 23 | 3087838016 |
| 24 | 4359706245 |
| 25 | 6067321574 |
| 26 | 8332617060 |
| 27 | 11304678954 |