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A215291 Number of permutations of 0..floor((n*7-1)/2) on even squares of an nX7 array such that each row and column of even squares is increasing 1

%I

%S 1,35,2310,210210,42882840,5703417720,2061378118800,337653735859440,

%T 173457547735792320,32436561426593163840,21174123919831066023840,

%U 4340695403565368534887200,3373030378241974592216989200

%N Number of permutations of 0..floor((n*7-1)/2) on even squares of an nX7 array such that each row and column of even squares is increasing

%C Column 7 of A215292

%H R. H. Hardin, <a href="/A215291/b215291.txt">Table of n, a(n) for n = 1..210</a>

%F f3=floor((n+1)/2)

%F f4=floor(n/2)

%F a(n) = A060854(4,f3)*A060854(3,f4)*binomial(4*f3+3*f4,4*f3)

%e Some solutions for n=3

%e ..0..x..3..x..5..x..6....0..x..1..x..2..x..3....1..x..2..x..3..x..5

%e ..x..1..x..8..x.10..x....x..5..x..8..x.10..x....x..0..x..6..x.10..x

%e ..2..x..4..x..7..x..9....4..x..6..x..7..x..9....4..x..7..x..8..x..9

%K nonn

%O 1,2

%A _R. H. Hardin_ Aug 07 2012

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Last modified January 27 06:18 EST 2022. Contains 350601 sequences. (Running on oeis4.)