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 | 25 |
| 4 | 49 |
| 5 | 141 |
| 6 | 389 |
| 7 | 1009 |
| 8 | 2761 |
| 9 | 7441 |
| 10 | 19925 |
| 11 | 53769 |
| 12 | 144721 |
| 13 | 389325 |
| 14 | 1048325 |
| 15 | 2821665 |
| 16 | 7594761 |
| 17 | 20444065 |
| 18 | 55029413 |
| 19 | 148124153 |
| 20 | 398713969 |
| 21 | 1073231821 |
| 22 | 2888859781 |
| 23 | 7776063377 |
| 24 | 20931130057 |
| 25 | 56341150641 |
| 26 | 151655712629 |
| 27 | 408217654249 |
| 28 | 1098815597201 |