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 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 16 |
| 5 | 46 |
| 6 | 132 |
| 7 | 386 |
| 8 | 1136 |
| 9 | 3366 |
| 10 | 10012 |
| 11 | 29866 |
| 12 | 89256 |
| 13 | 267086 |
| 14 | 799892 |
| 15 | 2396946 |
| 16 | 7185376 |
| 17 | 21545206 |
| 18 | 64613772 |
| 19 | 193797626 |
| 20 | 581305496 |
| 21 | 1743741726 |
| 22 | 5230875652 |
| 23 | 15691927906 |
| 24 | 47074385616 |
| 25 | 141220360646 |
| 26 | 423655489532 |