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A198975 Number of n X n 0..5 arrays with values 0..5 introduced in row major order and no element equal to any horizontal or vertical neighbor.

%I A198975 #11 Jul 22 2025 13:07:22
%S A198975 1,4,1835,53082012,30525244435834,310387893630465965693,
%T A198975 55676868201599759013090066735
%N A198975 Number of n X n 0..5 arrays with values 0..5 introduced in row major order and no element equal to any horizontal or vertical neighbor.
%C A198975 Diagonal of A198982
%H A198975 Jean-François Alcover, <a href="/A198975/b198975.txt">Table of n, a(n) for n = 1..13</a>
%e A198975 Some solutions with all values from 0 to 5 for n=4
%e A198975 ..0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1
%e A198975 ..1..2..3..0....1..0..2..0....1..2..3..0....1..0..2..0....1..0..2..0
%e A198975 ..4..3..2..3....0..3..4..3....4..3..2..5....0..2..1..3....3..4..5..2
%e A198975 ..2..1..5..2....5..2..1..2....1..4..1..4....4..3..5..0....4..2..3..5
%t A198975 A198982 = Cases[Import["https://oeis.org/A198982/b198982.txt", "Table"], {_, _}][[All, 2]];
%t A198975 a[n_] := A198982[[2 n^2 - 2 n + 1]];
%t A198975 Table[a[n], {n, 1, 13}] (* _Jean-François Alcover_, Sep 23 2019 *)
%K A198975 nonn
%O A198975 1,2
%A A198975 _R. H. Hardin_ Nov 01 2011