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 | 2 |
| 6 | 11 |
| 7 | 48 |
| 8 | 208 |
| 9 | 858 |
| 10 | 3507 |
| 11 | 14144 |
| 12 | 56698 |
| 13 | 226100 |
| 14 | 898942 |
| 15 | 3565920 |
| 16 | 14124496 |
| 17 | 55887930 |
| 18 | 220985795 |
| 19 | 873396480 |
| 20 | 3450940830 |
| 21 | 13633173180 |
| 22 | 53855628554 |
| 23 | 212750148000 |
| 24 | 840496068160 |
| 25 | 3320817060132 |
| 26 | 13122294166126 |
| 27 | 51860761615488 |