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 A206394 #7 Jul 22 2025 19:26:45 %S A206394 15,1201,12428,151630,1787258,21983256,268956972,3301485294, %T A206394 40603817198,499201392028,6147736324286,75698270712532, %U A206394 932481394642188,11487787221488608,141538253304943642,1744036023952329892 %N A206394 Number of nX6 0..5 arrays with no element equal to another within a city block distance of two, and new values 0..5 introduced in row major order. %C A206394 Column 6 of A206396 %H A206394 R. H. Hardin, <a href="/A206394/b206394.txt">Table of n, a(n) for n = 1..31</a> %e A206394 Some solutions for n=4 %e A206394 ..0..1..2..0..1..3....0..1..2..0..3..4....0..1..2..0..3..1....0..1..2..0..1..2 %e A206394 ..2..3..4..5..2..4....2..5..4..1..2..5....2..3..4..1..2..4....2..3..4..5..3..4 %e A206394 ..4..5..0..1..3..5....1..3..0..5..4..0....1..5..0..3..5..0....5..0..1..2..0..1 %e A206394 ..0..1..2..4..0..1....5..4..2..3..1..2....0..4..1..2..4..1....3..4..5..3..4..2 %K A206394 nonn %O A206394 1,1 %A A206394 _R. H. Hardin_ Feb 07 2012