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 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 18 |
| 5 | 49 |
| 6 | 127 |
| 7 | 331 |
| 8 | 883 |
| 9 | 2376 |
| 10 | 6439 |
| 11 | 17591 |
| 12 | 48347 |
| 13 | 133589 |
| 14 | 370883 |
| 15 | 1033997 |
| 16 | 2893498 |
| 17 | 8124303 |
| 18 | 22880569 |
| 19 | 64616728 |
| 20 | 182943204 |
| 21 | 519146325 |
| 22 | 1476337528 |
| 23 | 4206621803 |
| 24 | 12008000771 |
| 25 | 34335363519 |
| 26 | 98332343337 |
| 27 | 282026580873 |