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 | 4 |
| 2 | 13 |
| 3 | 38 |
| 4 | 104 |
| 5 | 272 |
| 6 | 688 |
| 7 | 1696 |
| 8 | 4096 |
| 9 | 9728 |
| 10 | 22784 |
| 11 | 52736 |
| 12 | 120832 |
| 13 | 274432 |
| 14 | 618496 |
| 15 | 1384448 |
| 16 | 3080192 |
| 17 | 6815744 |
| 18 | 15007744 |
| 19 | 32899072 |
| 20 | 71827456 |
| 21 | 156237824 |
| 22 | 338690048 |
| 23 | 731906048 |
| 24 | 1577058304 |
| 25 | 3388997632 |
| 26 | 7264534528 |
| 27 | 15535702016 |
| 28 | 33151778816 |