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 | 4 |
| 2 | 10 |
| 3 | 30 |
| 4 | 85 |
| 5 | 246 |
| 6 | 707 |
| 7 | 2037 |
| 8 | 5864 |
| 9 | 16886 |
| 10 | 48620 |
| 11 | 139997 |
| 12 | 403104 |
| 13 | 1160693 |
| 14 | 3342081 |
| 15 | 9623140 |
| 16 | 27708726 |
| 17 | 79784098 |
| 18 | 229729153 |
| 19 | 661478734 |
| 20 | 1904652103 |
| 21 | 5484227157 |
| 22 | 15791202736 |
| 23 | 45468956106 |
| 24 | 130922641160 |
| 25 | 376976720745 |
| 26 | 1085461206128 |
| 27 | 3125460977225 |