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 | 4 |
| 2 | 18 |
| 3 | 64 |
| 4 | 215 |
| 5 | 660 |
| 6 | 1938 |
| 7 | 5400 |
| 8 | 14527 |
| 9 | 37728 |
| 10 | 95278 |
| 11 | 234344 |
| 12 | 563506 |
| 13 | 1326796 |
| 14 | 3066040 |
| 15 | 6963048 |
| 16 | 15564661 |
| 17 | 34282360 |
| 18 | 74486376 |
| 19 | 159785472 |
| 20 | 338703796 |
| 21 | 709957616 |
| 22 | 1472529670 |
| 23 | 3023894672 |
| 24 | 6151408852 |
| 25 | 12402137024 |
| 26 | 24792822174 |
| 27 | 49162962280 |
| 28 | 96737562642 |