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 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 12 |
| 5 | 32 |
| 6 | 80 |
| 7 | 200 |
| 8 | 520 |
| 9 | 1336 |
| 10 | 3472 |
| 11 | 9072 |
| 12 | 23744 |
| 13 | 62432 |
| 14 | 164544 |
| 15 | 434688 |
| 16 | 1150944 |
| 17 | 3052768 |
| 18 | 8110784 |
| 19 | 21581120 |
| 20 | 57498496 |
| 21 | 153378048 |
| 22 | 409583616 |
| 23 | 1094848768 |
| 24 | 2929288960 |
| 25 | 7843943680 |
| 26 | 21020501504 |
| 27 | 56371941888 |
| 28 | 151276652544 |