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 | 5 |
| 1 | 19 |
| 2 | 61 |
| 3 | 187 |
| 4 | 565 |
| 5 | 1699 |
| 6 | 5101 |
| 7 | 15307 |
| 8 | 45925 |
| 9 | 137779 |
| 10 | 413341 |
| 11 | 1240027 |
| 12 | 3720085 |
| 13 | 11160259 |
| 14 | 33480781 |
| 15 | 100442347 |
| 16 | 301327045 |
| 17 | 903981139 |
| 18 | 2711943421 |
| 19 | 8135830267 |
| 20 | 24407490805 |
| 21 | 73222472419 |
| 22 | 219667417261 |
| 23 | 659002251787 |
| 24 | 1977006755365 |
| 25 | 5931020266099 |
| 26 | 17793060798301 |
| 27 | 53379182394907 |