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) |
|---|---|
| 3 | 1 |
| 4 | 3 |
| 5 | 12 |
| 6 | 58 |
| 7 | 327 |
| 8 | 2109 |
| 9 | 15366 |
| 10 | 125316 |
| 11 | 1135329 |
| 12 | 11348623 |
| 13 | 124359336 |
| 14 | 1484796894 |
| 15 | 19204214363 |
| 16 | 267627706257 |
| 17 | 3998828758938 |
| 18 | 63777662250440 |
| 19 | 1081442839245381 |
| 20 | 19426122224995107 |
| 21 | 368492543629967292 |