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 | 3 |
| 2 | 9 |
| 3 | 28 |
| 4 | 87 |
| 5 | 273 |
| 6 | 857 |
| 7 | 2692 |
| 8 | 8457 |
| 9 | 26568 |
| 10 | 83465 |
| 11 | 262213 |
| 12 | 823766 |
| 13 | 2587937 |
| 14 | 8130243 |
| 15 | 25541911 |
| 16 | 80242279 |
| 17 | 252088554 |
| 18 | 791959549 |
| 19 | 2488014301 |
| 20 | 7816327450 |
| 21 | 24555716894 |
| 22 | 77144059797 |
| 23 | 242355211526 |
| 24 | 761381352089 |
| 25 | 2391950062303 |
| 26 | 7514532743484 |
| 27 | 23607600862089 |
| 28 | 74165465437218 |