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 | 6 |
| 4 | 15 |
| 5 | 42 |
| 6 | 107 |
| 7 | 294 |
| 8 | 780 |
| 9 | 2128 |
| 10 | 5781 |
| 11 | 15918 |
| 12 | 43885 |
| 13 | 122010 |
| 14 | 340323 |
| 15 | 954394 |
| 16 | 2685930 |
| 17 | 7588770 |
| 18 | 21507696 |
| 19 | 61144062 |
| 20 | 174283887 |
| 21 | 498012094 |
| 22 | 1426213191 |
| 23 | 4092816966 |
| 24 | 11767176070 |
| 25 | 33890202192 |
| 26 | 97761428205 |
| 27 | 282424564744 |