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 A203723 Number of (n+1)X4 0..2 arrays with column and row pair sums b(i,j)=a(i,j)+a(i,j-1) and c(i,j)=a(i,j)+a(i-1,j) nondecreasing in column and row directions, respectively 1

%I

%S 326,1632,6249,20290,58048,151649,367595,839916,1825184,3804580,

%T 7650824,14922063,28339038,52596875,95678477,171041225,301149679,

%U 523280917,898900092,1528951772,2578559796,4317146589,7183260955,11889652446

%N Number of (n+1)X4 0..2 arrays with column and row pair sums b(i,j)=a(i,j)+a(i,j-1) and c(i,j)=a(i,j)+a(i-1,j) nondecreasing in column and row directions, respectively

%C Column 3 of A203728

%H R. H. Hardin, <a href="/A203723/b203723.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 9*a(n-1) -30*a(n-2) +31*a(n-3) +67*a(n-4) -220*a(n-5) +136*a(n-6) +300*a(n-7) -546*a(n-8) +78*a(n-9) +572*a(n-10) -494*a(n-11) -130*a(n-12) +404*a(n-13) -152*a(n-14) -100*a(n-15) +99*a(n-16) -15*a(n-17) -14*a(n-18) +7*a(n-19) -a(n-20) for n>23

%e Some solutions for n=4

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

%e ..1..2..2..2....2..2..2..2....1..2..2..2....2..2..2..2....2..2..2..2

%e ..1..2..2..2....2..2..2..2....1..2..2..2....2..2..2..2....2..2..2..2

%e ..2..2..2..2....2..2..2..2....1..2..2..2....2..2..2..2....2..2..2..2

%e ..2..2..2..2....2..2..2..2....2..2..2..2....2..2..2..2....2..2..2..2

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 05 2012

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Last modified December 5 21:40 EST 2022. Contains 358594 sequences. (Running on oeis4.)