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 | 4 |
| 2 | 9 |
| 3 | 21 |
| 4 | 51 |
| 5 | 127 |
| 6 | 324 |
| 7 | 844 |
| 8 | 2243 |
| 9 | 6073 |
| 10 | 16737 |
| 11 | 46905 |
| 12 | 133556 |
| 13 | 386062 |
| 14 | 1132107 |
| 15 | 3365627 |
| 16 | 10137559 |
| 17 | 30920943 |
| 18 | 95457177 |
| 19 | 298128257 |
| 20 | 941574130 |
| 21 | 3006037464 |
| 22 | 9697650031 |
| 23 | 31602766791 |
| 24 | 104000078093 |
| 25 | 345512414521 |
| 26 | 1158493006765 |