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 | 7 |
| 2 | 26 |
| 3 | 81 |
| 4 | 270 |
| 5 | 841 |
| 6 | 2480 |
| 7 | 7479 |
| 8 | 22404 |
| 9 | 66535 |
| 10 | 197470 |
| 11 | 592419 |
| 12 | 1772034 |
| 13 | 5317217 |
| 14 | 15955046 |
| 15 | 47860367 |
| 16 | 143540614 |
| 17 | 430579631 |
| 18 | 1291494336 |
| 19 | 3874347869 |
| 20 | 11622575710 |
| 21 | 34869569547 |
| 22 | 104608356834 |
| 23 | 313820413899 |
| 24 | 941454837836 |
| 25 | 2824364840671 |
| 26 | 8473084264392 |
| 27 | 25419236780193 |
| 28 | 76257724291584 |