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 | 2 |
| 1 | 9 |
| 2 | 38 |
| 3 | 153 |
| 4 | 596 |
| 5 | 2268 |
| 6 | 8480 |
| 7 | 31275 |
| 8 | 114086 |
| 9 | 412443 |
| 10 | 1479926 |
| 11 | 5276664 |
| 12 | 18711758 |
| 13 | 66041901 |
| 14 | 232129190 |
| 15 | 812934621 |
| 16 | 2837740232 |
| 17 | 9877082004 |
| 18 | 34288573484 |
| 19 | 118752490863 |
| 20 | 410394698534 |
| 21 | 1415492232255 |
| 22 | 4873386985130 |
| 23 | 16750755602928 |
| 24 | 57487476629594 |
| 25 | 197013756414033 |