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 | 3 |
| 2 | 6 |
| 3 | 12 |
| 4 | 26 |
| 5 | 60 |
| 6 | 140 |
| 7 | 320 |
| 8 | 712 |
| 9 | 1552 |
| 10 | 3344 |
| 11 | 7168 |
| 12 | 15328 |
| 13 | 32704 |
| 14 | 69568 |
| 15 | 147456 |
| 16 | 311424 |
| 17 | 655616 |
| 18 | 1376512 |
| 19 | 2883584 |
| 20 | 6028800 |
| 21 | 12581888 |
| 22 | 26213376 |
| 23 | 54525952 |
| 24 | 113248256 |
| 25 | 234885120 |
| 26 | 486543360 |
| 27 | 1006632960 |
| 28 | 2080366592 |