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 | 5 |
| 3 | 15 |
| 4 | 46 |
| 5 | 128 |
| 6 | 384 |
| 7 | 1114 |
| 8 | 3332 |
| 9 | 9903 |
| 10 | 29671 |
| 11 | 88721 |
| 12 | 266151 |
| 13 | 797593 |
| 14 | 2392649 |
| 15 | 7175709 |
| 16 | 21526834 |
| 17 | 64573556 |
| 18 | 193720536 |
| 19 | 581141026 |
| 20 | 1743422288 |
| 21 | 5230207428 |
| 22 | 15690619684 |
| 23 | 47071679294 |
| 24 | 141215037738 |
| 25 | 423644574301 |
| 26 | 1270933715189 |
| 27 | 3812799550089 |
| 28 | 11438398630159 |