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 | 2 |
| 1 | 4 |
| 2 | 10 |
| 3 | 24 |
| 4 | 56 |
| 5 | 130 |
| 6 | 302 |
| 7 | 702 |
| 8 | 1632 |
| 9 | 3794 |
| 10 | 8820 |
| 11 | 20504 |
| 12 | 47666 |
| 13 | 110810 |
| 14 | 257602 |
| 15 | 598852 |
| 16 | 1392162 |
| 17 | 3236384 |
| 18 | 7523680 |
| 19 | 17490434 |
| 20 | 40660326 |
| 21 | 94523790 |
| 22 | 219741152 |
| 23 | 510836202 |
| 24 | 1187550092 |
| 25 | 2760719024 |
| 26 | 6417893090 |
| 27 | 14919791314 |
| 28 | 34684306786 |