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 | 2 |
| 1 | 5 |
| 2 | 15 |
| 3 | 48 |
| 4 | 169 |
| 5 | 618 |
| 6 | 2319 |
| 7 | 8804 |
| 8 | 33649 |
| 9 | 129046 |
| 10 | 495779 |
| 11 | 1906520 |
| 12 | 7335029 |
| 13 | 28227578 |
| 14 | 108642983 |
| 15 | 418176700 |
| 16 | 1609656953 |
| 17 | 6196050718 |
| 18 | 23850681323 |
| 19 | 91809753632 |
| 20 | 353409321213 |