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) |
|---|---|
| 2 | 1 |
| 3 | 0 |
| 4 | 2 |
| 5 | 3 |
| 6 | 7 |
| 7 | 15 |
| 8 | 33 |
| 9 | 72 |
| 10 | 157 |
| 11 | 341 |
| 12 | 738 |
| 13 | 1591 |
| 14 | 3417 |
| 15 | 7312 |
| 16 | 15593 |
| 17 | 33145 |
| 18 | 70242 |
| 19 | 148443 |
| 20 | 312893 |
| 21 | 657944 |
| 22 | 1380437 |
| 23 | 2890349 |
| 24 | 6040258 |
| 25 | 12600623 |
| 26 | 26243057 |
| 27 | 54572320 |
| 28 | 113321233 |
| 29 | 235002417 |
| 30 | 486735682 |
| 31 | 1006950771 |
| 32 | 2080889013 |
| 33 | 4295799336 |
| 34 | 8859716317 |
| 35 | 18255789317 |
| 36 | 37584488418 |
| 37 | 77315114215 |
| 38 | 158923017417 |
| 39 | 326432444848 |