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 | 5 |
| 3 | 26 |
| 4 | 150 |
| 5 | 925 |
| 6 | 5967 |
| 7 | 39772 |
| 8 | 271758 |
| 9 | 1893431 |
| 10 | 13400897 |
| 11 | 96078789 |
| 12 | 696333585 |
| 13 | 5093266409 |
| 14 | 37549674939 |
| 15 | 278739057687 |
| 16 | 2081637677823 |
| 17 | 15628794649931 |
| 18 | 117897848681271 |
| 19 | 893167062280029 |
| 20 | 6792410218680749 |
| 21 | 51835002735642287 |
| 22 | 396821349652564273 |