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) |
|---|---|
| 2 | 1 |
| 3 | 6 |
| 4 | 28 |
| 5 | 121 |
| 6 | 508 |
| 7 | 2109 |
| 8 | 8723 |
| 9 | 36065 |
| 10 | 149277 |
| 11 | 618961 |
| 12 | 2571503 |
| 13 | 10704390 |
| 14 | 44641793 |
| 15 | 186492242 |
| 16 | 780275596 |
| 17 | 3269135406 |
| 18 | 13713525610 |
| 19 | 57588530626 |
| 20 | 242068874444 |
| 21 | 1018378855512 |
| 22 | 4287501276956 |
| 23 | 18062827159136 |
| 24 | 76141329903018 |