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 | 0 |
| 4 | 1 |
| 5 | 8 |
| 6 | 43 |
| 7 | 196 |
| 8 | 820 |
| 9 | 3265 |
| 10 | 12615 |
| 11 | 47840 |
| 12 | 179355 |
| 13 | 667875 |
| 14 | 2478022 |
| 15 | 9180616 |
| 16 | 34011401 |
| 17 | 126120212 |
| 18 | 468411235 |
| 19 | 1743105373 |
| 20 | 6500874434 |
| 21 | 24300686879 |
| 22 | 91049069203 |
| 23 | 341924710480 |
| 24 | 1286932932251 |
| 25 | 4854167659403 |
| 26 | 18346988061078 |