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 | 2 |
| 3 | 9 |
| 4 | 32 |
| 5 | 208 |
| 6 | 972 |
| 7 | 7843 |
| 8 | 43690 |
| 9 | 409968 |
| 10 | 2604166 |
| 11 | 27447010 |
| 12 | 193491763 |
| 13 | 2241278030 |
| 14 | 17224712961 |
| 15 | 216027868615 |
| 16 | 1787142709274 |
| 17 | 24006211998207 |
| 18 | 211773735868781 |
| 19 | 3021737893128258 |
| 20 | 28218694885361552 |
| 21 | 424936725846414486 |