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A183715 1/20 of the number of (n+1) X 6 0..4 arrays with every 2X2 subblock strictly increasing clockwise or counterclockwise with one decrease. 1

%I

%S 70,559,4012,30113,224640,1683197,12606120,94463507,707826798,

%T 5304230928,39748015308,297860692491,2232084261366,16726639262465,

%U 125344918169856,939301219166473,7038871324696794,52747415646208987,395274995490521924

%N 1/20 of the number of (n+1) X 6 0..4 arrays with every 2X2 subblock strictly increasing clockwise or counterclockwise with one decrease.

%C Column 5 of A183719.

%H R. H. Hardin, <a href="/A183715/b183715.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n)=2*a(n-1)+54*a(n-2)-2*a(n-3)-738*a(n-4)-312*a(n-5)+4078*a(n-6)+2098*a(n-7)-10802*a(n-8)-4874*a(n-9)+14854*a(n-10)+4874*a(n-11)-10802*a(n-12)-2098*a(n-13)+4078*a(n-14)+312*a(n-15)-738*a(n-16)+2*a(n-17)+54*a(n-18)-2*a(n-19)-a(n-20).

%e Some solutions for 3 X 6:

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

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

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

%e ...

%e ...L..R..L..R..L.......R..L..R..L..R.......R..L..R..L..R.......L..R..L..R..L...

%e ...R..L..R..L..R.......L..R..L..R..L.......L..R..L..R..L.......R..L..R..L..R...

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 06 2011

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Last modified September 27 06:29 EDT 2022. Contains 357052 sequences. (Running on oeis4.)