A198975 - OEIS

%I #9 Sep 23 2019 05:34:46

%S 1,4,1835,53082012,30525244435834,310387893630465965693,

%T 55676868201599759013090066735

%N 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 Diagonal of A198982

%H Jean-François Alcover, <a href="/A198975/b198975.txt">Table of n, a(n) for n = 1..13</a>

%e Some solutions with all values from 0 to 5 for n=4

%e ..0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1

%e ..1..2..3..0....1..0..2..0....1..2..3..0....1..0..2..0....1..0..2..0

%e ..4..3..2..3....0..3..4..3....4..3..2..5....0..2..1..3....3..4..5..2

%e ..2..1..5..2....5..2..1..2....1..4..1..4....4..3..5..0....4..2..3..5

%t A198982 = Cases[Import["https://oeis.org/A198982/b198982.txt", "Table"], {_, _}][[All, 2]];

%t a[n_] := A198982[[2 n^2 - 2 n + 1]];

%t Table[a[n], {n, 1, 13}] (* _Jean-François Alcover_, Sep 23 2019 *)

%K nonn

%O 1,2

%A _R. H. Hardin_ Nov 01 2011