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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 11 |
| 5 | 81 |
| 6 | 351 |
| 7 | 1149 |
| 8 | 3529 |
| 9 | 12601 |
| 10 | 52724 |
| 11 | 222641 |
| 12 | 879308 |
| 13 | 3295384 |
| 14 | 12303201 |
| 15 | 47320365 |
| 16 | 186738507 |
| 17 | 739129809 |
| 18 | 2894481813 |
| 19 | 11237844615 |
| 20 | 43647142533 |
| 21 | 170543919327 |
| 22 | 669744238998 |
| 23 | 2633027605209 |
| 24 | 10337488816041 |
| 25 | 40544676533466 |