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 | 0 |
| 3 | 2 |
| 4 | 2 |
| 5 | 2 |
| 6 | 29 |
| 7 | 56 |
| 8 | 191 |
| 9 | 380 |
| 10 | 5097 |
| 11 | 14288 |
| 12 | 74359 |
| 13 | 283884 |
| 14 | 1106529 |
| 15 | 13588409 |
| 16 | 53640963 |
| 17 | 350573155 |
| 18 | 1867738775 |
| 19 | 10770352150 |
| 20 | 50050737949 |
| 21 | 744605446778 |
| 22 | 3615378756421 |
| 23 | 29368052533243 |
| 24 | 195027586980839 |
| 25 | 1442227919200245 |
| 26 | 8964685271444243 |
| 27 | 61478734886319324 |