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 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | 66 |
| 7 | 2096 |
| 8 | 25676 |
| 9 | 187984 |
| 10 | 983172 |
| 11 | 4073312 |
| 12 | 14196011 |
| 13 | 43309138 |
| 14 | 118818916 |
| 15 | 298926225 |
| 16 | 699619679 |
| 17 | 1540212590 |
| 18 | 3217045155 |
| 19 | 6419240369 |
| 20 | 12304959047 |
| 21 | 22763742133 |
| 22 | 40797668697 |
| 23 | 71065355815 |
| 24 | 120643462032 |
| 25 | 200077436639 |
| 26 | 324808463585 |
| 27 | 517088445952 |
| 28 | 808515893580 |