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) |
|---|---|
| 1 | 3 |
| 2 | 7 |
| 3 | 11 |
| 4 | 21 |
| 5 | 43 |
| 6 | 89 |
| 7 | 189 |
| 8 | 427 |
| 9 | 1043 |
| 10 | 2691 |
| 11 | 7033 |
| 12 | 18017 |
| 13 | 44505 |
| 14 | 105505 |
| 15 | 240269 |
| 16 | 527037 |
| 17 | 1116025 |
| 18 | 2283323 |
| 19 | 4509663 |
| 20 | 8574253 |
| 21 | 15613037 |
| 22 | 26989461 |
| 23 | 43596475 |
| 24 | 63714863 |
| 25 | 77517777 |
| 26 | 54160585 |
| 27 | -87072619 |
| 28 | -539390367 |
| 29 | -1742001767 |
| 30 | -4661299495 |