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 | 3 |
| 2 | 9 |
| 3 | 27 |
| 4 | 79 |
| 5 | 225 |
| 6 | 626 |
| 7 | 1710 |
| 8 | 4605 |
| 9 | 12259 |
| 10 | 32320 |
| 11 | 84504 |
| 12 | 219356 |
| 13 | 565816 |
| 14 | 1451349 |
| 15 | 3704271 |
| 16 | 9412153 |
| 17 | 23818707 |
| 18 | 60055275 |
| 19 | 150913073 |
| 20 | 378064818 |
| 21 | 944442242 |
| 22 | 2353140149 |
| 23 | 5848794543 |
| 24 | 14504575980 |
| 25 | 35894673012 |
| 26 | 88654500384 |
| 27 | 218560230944 |