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 A264185 Number of (n+1) X (3+1) arrays of permutations of 0..n*4+3 with each element having index change +-(.,.) 0,0 1,-1 or 2,2. 1

%I

%S 8,81,720,7056,70560,705600,7056000,70560000,705600000,7056000000,

%T 70560000000,705600000000,7056000000000,70560000000000,

%U 705600000000000,7056000000000000,70560000000000000,705600000000000000

%N Number of (n+1) X (3+1) arrays of permutations of 0..n*4+3 with each element having index change +-(.,.) 0,0 1,-1 or 2,2.

%H R. H. Hardin, <a href="/A264185/b264185.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 10*a(n-1) for n>4.

%F Conjectures from _Colin Barker_, Jan 05 2019: (Start)

%F G.f.: x*(8 + x - 90*x^2 - 144*x^3) / (1 - 10*x).

%F a(n) = 441*2^n * 5^(n-4) for n>3.

%F (End)

%e Some solutions for n=4:

%e ..0.11..2..6...10.11..2..3....0.11..2..6....0..1..2..6...10..4..2..3

%e ..1..5..3..7....4..8..6..7....1..5..3..7....4.15..3.10....1.15..6..7

%e .18..9.10.14...18.12..0..1....8.19.13.14....5.19..7.11...18..9..0.11

%e .12.16..4.15....9.16.14..5...12.10..4.18...12.13.17.18...12.13.17..5

%e .13.17..8.19...13.17.15.19...16.17.15..9...16.14..8..9...16.14..8.19

%Y Column 3 of A264190.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 06 2015

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Last modified August 17 11:49 EDT 2022. Contains 356189 sequences. (Running on oeis4.)