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 | -2 |
| 2 | 4 |
| 3 | 4 |
| 4 | 4 |
| 5 | 16 |
| 6 | 28 |
| 7 | 52 |
| 8 | 112 |
| 9 | 220 |
| 10 | 436 |
| 11 | 880 |
| 12 | 1756 |
| 13 | 3508 |
| 14 | 7024 |
| 15 | 14044 |
| 16 | 28084 |
| 17 | 56176 |
| 18 | 112348 |
| 19 | 224692 |
| 20 | 449392 |
| 21 | 898780 |
| 22 | 1797556 |
| 23 | 3595120 |
| 24 | 7190236 |
| 25 | 14380468 |
| 26 | 28760944 |
| 27 | 57521884 |
| 28 | 115043764 |
| 29 | 230087536 |
| 30 | 460175068 |
| 31 | 920350132 |
| 32 | 1840700272 |
| 33 | 3681400540 |