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) |
|---|---|
| 3 | 1 |
| 4 | 2 |
| 5 | 3 |
| 6 | 11 |
| 7 | 29 |
| 8 | 122 |
| 9 | 479 |
| 10 | 2113 |
| 11 | 9369 |
| 12 | 43392 |
| 13 | 203595 |
| 14 | 975563 |
| 15 | 4736005 |
| 16 | 23296394 |
| 17 | 115811855 |
| 18 | 581324861 |
| 19 | 2942579633 |
| 20 | 15008044522 |
| 21 | 77064865555 |
| 22 | 398150807179 |
| 23 | 2068470765261 |
| 24 | 10800665952376 |
| 25 | 56658467018647 |
| 26 | 298489772155137 |
| 27 | 1578702640556193 |