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A209499 Number of nX4 0..4 arrays with every 2X2 subblock containing exactly one value repeat, and new values 0..4 introduced in row major order.

%I A209499 #9 Jul 22 2025 21:46:01
%S A209499 15,690,78135,9502354,1165032679,142937856372,17538444837670,
%T A209499 2151975129988088,264048573957784964,32398910709148727392,
%U A209499 3975364904849935772656,487779550353892225564624
%N A209499 Number of nX4 0..4 arrays with every 2X2 subblock containing exactly one value repeat, and new values 0..4 introduced in row major order.
%C A209499 Column 4 of A209503
%H A209499 R. H. Hardin, <a href="/A209499/b209499.txt">Table of n, a(n) for n = 1..210</a>
%F A209499 Empirical: a(n) = 118*a(n-1) +1604*a(n-2) -127784*a(n-3) -79452*a(n-4) +37606360*a(n-5) -178547756*a(n-6) -2931053296*a(n-7) +18312307424*a(n-8) +74021561744*a(n-9) -495233537616*a(n-10) -1023076292096*a(n-11) +5490220477440*a(n-12) +8804921243328*a(n-13) -24309394624512*a(n-14) -36012394278144*a(n-15) +28360887229440*a(n-16) +27667991881728*a(n-17) -15907925311488*a(n-18) for n>19
%e A209499 Some.solutions.for.n=4
%e A209499 ..0..1..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
%e A209499 ..1..2..1..2....1..2..3..2....1..2..3..4....1..2..1..3....1..2..3..1
%e A209499 ..0..0..0..2....0..0..3..4....1..3..4..0....3..2..0..1....4..4..4..1
%e A209499 ..1..2..1..2....4..3..4..0....2..2..4..3....0..0..3..3....0..2..1..0
%K A209499 nonn
%O A209499 1,1
%A A209499 _R. H. Hardin_ Mar 09 2012