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) |
|---|---|
| 4 | 1 |
| 5 | 5 |
| 6 | 20 |
| 7 | 84 |
| 8 | 388 |
| 9 | 1951 |
| 10 | 10529 |
| 11 | 60478 |
| 12 | 367953 |
| 13 | 2362503 |
| 14 | 15955673 |
| 15 | 113015123 |
| 16 | 837307541 |
| 17 | 6473306155 |
| 18 | 52110629576 |
| 19 | 435951806195 |
| 20 | 3783475965645 |
| 21 | 34007779661168 |
| 22 | 316120859847935 |
| 23 | 3034730002671251 |
| 24 | 30048957645720682 |
| 25 | 306529788241138211 |
| 26 | 3217941347005747296 |
| 27 | 34730178825735671711 |
| 28 | 384990885899299757336 |
| 29 | 4379518943963832643173 |
| 30 | 51083106730348426001558 |