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 | 1 |
| 2 | 9 |
| 3 | 25 |
| 4 | 97 |
| 5 | 321 |
| 6 | 1097 |
| 7 | 3641 |
| 8 | 12033 |
| 9 | 39361 |
| 10 | 127945 |
| 11 | 413337 |
| 12 | 1328609 |
| 13 | 4251521 |
| 14 | 13551753 |
| 15 | 43046713 |
| 16 | 136314625 |
| 17 | 430467201 |
| 18 | 1355971721 |
| 19 | 4261625369 |
| 20 | 13366006881 |
| 21 | 41841412801 |
| 22 | 130754415049 |
| 23 | 407953774905 |
| 24 | 1270932914177 |