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 | 3 |
| 3 | 12 |
| 4 | 56 |
| 5 | 277 |
| 6 | 1449 |
| 7 | 7872 |
| 8 | 43978 |
| 9 | 251049 |
| 10 | 1457910 |
| 11 | 8585724 |
| 12 | 51152973 |
| 13 | 307770236 |
| 14 | 1867362978 |
| 15 | 11412645576 |
| 16 | 70194232585 |
| 17 | 434157164246 |
| 18 | 2698676669337 |
| 19 | 16849393604484 |
| 20 | 105621663128839 |
| 21 | 664493496025485 |
| 22 | 4194246946152171 |
| 23 | 26553277765995984 |
| 24 | 168567628890184974 |
| 25 | 1072818569798746567 |