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 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 10 |
| 6 | 24 |
| 7 | 68 |
| 8 | 182 |
| 9 | 544 |
| 10 | 1574 |
| 11 | 4888 |
| 12 | 14864 |
| 13 | 47610 |
| 14 | 149964 |
| 15 | 491802 |
| 16 | 1592198 |
| 17 | 5318936 |
| 18 | 17593170 |
| 19 | 59679516 |
| 20 | 200805614 |
| 21 | 689988886 |
| 22 | 2354489616 |
| 23 | 8178944510 |
| 24 | 28240716098 |