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A223866 Number of 3Xn 0..3 arrays with rows and antidiagonals unimodal and columns nondecreasing 1

%I

%S 20,400,4884,41682,273959,1477240,6818350,27746619,101698292,

%T 341120712,1060013078,3081189588,8443340635,21952389700,54443494785,

%U 129382581759,295772387822,652604111790,1393875593290,2889329636208,5825806879833

%N Number of 3Xn 0..3 arrays with rows and antidiagonals unimodal and columns nondecreasing

%C Row 3 of A223864

%H R. H. Hardin, <a href="/A223866/b223866.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = (1/3629463552000)*n^18 + (7/403273728000)*n^17 + (667/951035904000)*n^16 + (3281/174356582400)*n^15 + (148069/402361344000)*n^14 + (1366301/249080832000)*n^13 + (3748907/57480192000)*n^12 + (1190879/1916006400)*n^11 + (344761547/73156608000)*n^10 + (684241027/24385536000)*n^9 + (104051693257/804722688000)*n^8 + (54794329/119750400)*n^7 + (786440609/628992000)*n^6 + (81330893999/31135104000)*n^5 + (895703793151/217945728000)*n^4 + (8582457311/1816214400)*n^3 + (317136049/79168320)*n^2 + (10267897/6126120)*n + 1

%e Some solutions for n=3

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 28 2013

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Last modified January 25 16:01 EST 2022. Contains 350572 sequences. (Running on oeis4.)