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.
%I A222556 #5 Jun 02 2025 08:27:45 %S A222556 2,20,102,427,1668,6372,24230,92279,352596 %N A222556 Number of (n+2)X1 arrays of occupancy after each element moves up to +-n places but not 0. %C A222556 Row 2 of A222555 %e A222556 Some solutions for n=3 %e A222556 ..1....3....0....0....2....0....0....2....1....2....0....0....3....2....1....1 %e A222556 ..3....0....0....1....0....2....0....1....1....1....1....3....0....0....0....0 %e A222556 ..0....1....3....0....2....1....4....1....1....0....2....0....0....3....4....3 %e A222556 ..0....1....1....1....1....1....0....1....2....1....0....1....2....0....0....0 %e A222556 ..1....0....1....3....0....1....1....0....0....1....2....1....0....0....0....1 %K A222556 nonn %O A222556 1,1 %A A222556 _R. H. Hardin_ Feb 24 2013