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 | 3 |
| 1 | 12 |
| 2 | 50 |
| 3 | 216 |
| 4 | 962 |
| 5 | 4392 |
| 6 | 20450 |
| 7 | 96696 |
| 8 | 462722 |
| 9 | 2234952 |
| 10 | 10873250 |
| 11 | 53199576 |
| 12 | 261449282 |
| 13 | 1289406312 |
| 14 | 6376734050 |
| 15 | 31605668856 |
| 16 | 156925904642 |
| 17 | 780248462472 |
| 18 | 3883804162850 |
| 19 | 19349526496536 |
| 20 | 96470430052802 |
| 21 | 481245665067432 |