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A218518 Number of nX4 arrays of the minimum value of corresponding elements and their horizontal or antidiagonal neighbors in a random 0..3 nX4 array.

%I A218518 #6 Jul 22 2025 23:57:26
%S A218518 36,1348,46140,1608968,55161270,1884162624,64278999490,2192134613268,
%T A218518 74751612059942,2548947544959236,86915544096055764,
%U A218518 2963690927218083408,101057383442299027280,3445903376402787417912,117500067196994800465952
%N A218518 Number of nX4 arrays of the minimum value of corresponding elements and their horizontal or antidiagonal neighbors in a random 0..3 nX4 array.
%C A218518 Column 4 of A218522
%H A218518 R. H. Hardin, <a href="/A218518/b218518.txt">Table of n, a(n) for n = 1..61</a>
%F A218518 Empirical: a(n) = 42*a(n-1) -245*a(n-2) -717*a(n-3) -5326*a(n-4) +43148*a(n-5) +128181*a(n-6) -176404*a(n-7) -1716466*a(n-8) -2364600*a(n-9) +12012574*a(n-10) +11501431*a(n-11) -58267109*a(n-12) -51447755*a(n-13) +49462902*a(n-14) +161410534*a(n-15) +79479210*a(n-16) -105405324*a(n-17) -153176469*a(n-18) -54313004*a(n-19) +39086790*a(n-20) +45585629*a(n-21) +16699655*a(n-22) +1770396*a(n-23) -935268*a(n-24) -336384*a(n-25) -57600*a(n-26) for n>27
%e A218518 Some solutions for n=3
%e A218518 ..3..0..2..2....0..0..1..3....1..1..1..0....2..2..3..2....3..0..2..2
%e A218518 ..0..0..1..1....1..3..2..3....1..0..0..0....3..2..1..0....0..0..3..3
%e A218518 ..3..3..1..3....2..2..1..1....1..0..2..3....3..0..0..0....2..2..2..2
%K A218518 nonn
%O A218518 1,1
%A A218518 _R. H. Hardin_ Oct 31 2012