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 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 0 |
| 10 | 0 |
| 11 | 0 |
| 12 | 1 |
| 13 | 0 |
| 14 | 1 |
| 15 | 1 |
| 16 | 3 |
| 17 | 4 |
| 18 | 12 |
| 19 | 23 |
| 20 | 73 |
| 21 | 192 |
| 22 | 651 |
| 23 | 2070 |
| 24 | 7290 |
| 25 | 25381 |
| 26 | 91441 |
| 27 | 329824 |
| 28 | 1204737 |
| 29 | 4412031 |
| 30 | 16248772 |
| 31 | 59995535 |
| 32 | 222231424 |
| 33 | 825028656 |
| 34 | 3069993552 |
| 35 | 11446245342 |
| 36 | 42758608761 |
| 37 | 160012226334 |
| 38 | 599822851579 |
| 39 | 2252137171764 |
| 40 | 8469193859271 |
| 41 | 31896058068930 |