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) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 2 |
| 3 | 2 |
| 4 | 6 |
| 5 | 12 |
| 6 | 26 |
| 7 | 60 |
| 8 | 130 |
| 9 | 300 |
| 10 | 672 |
| 11 | 1540 |
| 12 | 3514 |
| 13 | 8064 |
| 14 | 18552 |
| 15 | 42756 |
| 16 | 98802 |
| 17 | 228624 |
| 18 | 530024 |
| 19 | 1230372 |
| 20 | 2860000 |
| 21 | 6655792 |
| 22 | 15505932 |
| 23 | 36159552 |
| 24 | 84398626 |
| 25 | 197154984 |
| 26 | 460903796 |
| 27 | 1078251044 |
| 28 | 2524144224 |
| 29 | 5912535672 |
| 30 | 13857378300 |
| 31 | 32495267712 |