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 | -3 |
| 1 | -5 |
| 2 | -7 |
| 3 | -5 |
| 4 | 17 |
| 5 | 115 |
| 6 | 473 |
| 7 | 1675 |
| 8 | 5537 |
| 9 | 17635 |
| 10 | 54953 |
| 11 | 168955 |
| 12 | 515057 |
| 13 | 1561555 |
| 14 | 4717433 |
| 15 | 14217835 |
| 16 | 42784577 |
| 17 | 128615875 |
| 18 | 386371913 |
| 19 | 1160164315 |
| 20 | 3482590097 |
| 21 | 10451964595 |
| 22 | 31364282393 |
| 23 | 94109624395 |
| 24 | 282362427617 |
| 25 | 847154391715 |
| 26 | 2541597392873 |
| 27 | 7625060614075 |
| 28 | 22875718713137 |