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A203889 Number of (n+1)X2 0..4 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) such that rows of b(i,j) and columns of c(i,j) are lexicographically nondecreasing 1

%I #5 Mar 31 2012 12:36:58

%S 205,1940,16842,131432,940270,6287755,39889619,242721211,1428279867,

%T 8179225950,45807549072,251870313730,1363916141796,7292379512157,

%U 38576495950065,202251507089485,1052431144936985,5441816782194136

%N Number of (n+1)X2 0..4 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) such that rows of b(i,j) and columns of c(i,j) are lexicographically nondecreasing

%C Column 1 of A203896

%H R. H. Hardin, <a href="/A203889/b203889.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 28*a(n-1) -348*a(n-2) +2536*a(n-3) -12058*a(n-4) +39384*a(n-5) -90584*a(n-6) +147848*a(n-7) -170061*a(n-8) +134588*a(n-9) -69668*a(n-10) +21216*a(n-11) -2880*a(n-12)

%e Some solutions for n=4

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

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

%e ..1..3....1..4....3..3....1..1....2..4....4..4....4..4....4..4....4..3....1..4

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

%e ..2..4....2..3....3..4....2..2....3..4....4..4....4..4....4..4....3..4....1..4

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 07 2012

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Last modified April 15 17:47 EDT 2024. Contains 371693 sequences. (Running on oeis4.)