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 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 15 |
| 5 | 51 |
| 6 | 188 |
| 7 | 731 |
| 8 | 2950 |
| 9 | 12235 |
| 10 | 51822 |
| 11 | 223191 |
| 12 | 974427 |
| 13 | 4302645 |
| 14 | 19181100 |
| 15 | 86211885 |
| 16 | 390248055 |
| 17 | 1777495635 |
| 18 | 8140539950 |
| 19 | 37463689775 |
| 20 | 173164232965 |
| 21 | 803539474345 |
| 22 | 3741930523740 |
| 23 | 17481709707825 |
| 24 | 81912506777200 |
| 25 | 384847173838501 |
| 26 | 1812610804416698 |