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A209740 Number of nX4 0..5 arrays with every 2X2 subblock containing exactly one value repeat, and new values 0..5 introduced in row major order.

%I A209740 #7 Jul 22 2025 21:56:30
%S A209740 15,700,103373,20611956,4474325828,991613495404,220845828478730,
%T A209740 49242046909442868,10982471712866182098,2449579228342732267816,
%U A209740 546373088082223670747386,121867698385924682716244064
%N A209740 Number of nX4 0..5 arrays with every 2X2 subblock containing exactly one value repeat, and new values 0..5 introduced in row major order.
%C A209740 Column 4 of A209744
%H A209740 R. H. Hardin, <a href="/A209740/b209740.txt">Table of n, a(n) for n = 1..210</a>
%F A209740 Empirical: a(n) = 244*a(n-1) +137*a(n-2) -1195614*a(n-3) +21837944*a(n-4) +1404675270*a(n-5) -36835307408*a(n-6) -326873376252*a(n-7) +14507648154376*a(n-8) -8311682181464*a(n-9) -2334523810998832*a(n-10) +8762975100490480*a(n-11) +185277092995650336*a(n-12) -908553103605691712*a(n-13) -8222060623354335360*a(n-14) +40603092591766507264*a(n-15) +222543140644632005632*a(n-16) -906919532901077344256*a(n-17) -3774725396673218404352*a(n-18) +10011737555551519784960*a(n-19) +37478635910651820179456*a(n-20) -48928099712667888910336*a(n-21) -182050232765906369380352*a(n-22) +115193182556326721486848*a(n-23) +411251029796589926350848*a(n-24) -170990851031162490454016*a(n-25) -418387866292483163947008*a(n-26) +167007575033595637530624*a(n-27) +154943201526404521918464*a(n-28) -70873530141897822044160*a(n-29) for n>30
%e A209740 Some solutions for n=5
%e A209740 ..0..0..0..0....0..0..0..0....0..0..0..0....0..0..1..0....0..0..0..0
%e A209740 ..1..2..3..2....1..2..1..2....1..2..1..2....1..2..0..2....1..2..1..2
%e A209740 ..4..1..1..1....0..0..2..3....0..1..3..3....0..1..2..3....0..0..0..2
%e A209740 ..4..3..4..0....1..2..1..1....3..0..0..1....4..4..1..1....3..1..2..4
%e A209740 ..5..4..5..0....4..4..4..2....0..4..1..4....5..3..3..2....5..3..1..1
%K A209740 nonn
%O A209740 1,1
%A A209740 _R. H. Hardin_ Mar 12 2012