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 | 6 |
| 2 | 28 |
| 3 | 104 |
| 4 | 336 |
| 5 | 992 |
| 6 | 2752 |
| 7 | 7296 |
| 8 | 18688 |
| 9 | 46592 |
| 10 | 113664 |
| 11 | 272384 |
| 12 | 643072 |
| 13 | 1499136 |
| 14 | 3457024 |
| 15 | 7897088 |
| 16 | 17891328 |
| 17 | 40239104 |
| 18 | 89915392 |
| 19 | 199753728 |
| 20 | 441450496 |
| 21 | 970981376 |
| 22 | 2126512128 |
| 23 | 4638900224 |
| 24 | 10083106816 |
| 25 | 21843935232 |
| 26 | 47177531392 |
| 27 | 101602820096 |
| 28 | 218238025728 |