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) |
|---|---|
| 5 | 1 |
| 6 | 1 |
| 7 | 5 |
| 8 | 17 |
| 9 | 57 |
| 10 | 193 |
| 11 | 653 |
| 12 | 2205 |
| 13 | 7417 |
| 14 | 24805 |
| 15 | 82373 |
| 16 | 271437 |
| 17 | 887377 |
| 18 | 2878509 |
| 19 | 9268429 |
| 20 | 29636981 |
| 21 | 94163769 |
| 22 | 297435285 |
| 23 | 934521973 |
| 24 | 2922073641 |
| 25 | 9096981049 |
| 26 | 28209178729 |
| 27 | 87163760797 |
| 28 | 268462020889 |
| 29 | 824451264113 |
| 30 | 2525238433145 |