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 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 19 |
| 6 | 87 |
| 7 | 484 |
| 8 | 3110 |
| 9 | 22869 |
| 10 | 188938 |
| 11 | 1735684 |
| 12 | 17544342 |
| 13 | 193537909 |
| 14 | 2313316683 |
| 15 | 29780777636 |
| 16 | 410783319119 |
| 17 | 6043874244604 |
| 18 | 94478706232996 |
| 19 | 1563722273109142 |
| 20 | 27318062153696564 |
| 21 | 502345167237496931 |