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A188244 Number of arrangements of n+2 nonzero numbers x(i) in -4..4 with the sum of x(i)*x(i+1) equal to zero 1

%I

%S 64,144,1504,7092,58824,368588,2880240,20265640,156028036,1154193268,

%T 8877588920,67251222980,518783061524,3979996140580,30813430250120,

%U 238176520092556,1850203922639624,14371954026347848,111969329295785092

%N Number of arrangements of n+2 nonzero numbers x(i) in -4..4 with the sum of x(i)*x(i+1) equal to zero

%C Column 4 of A188249

%H R. H. Hardin, <a href="/A188244/b188244.txt">Table of n, a(n) for n = 1..59</a>

%e Some solutions for n=5

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

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 25 2011

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Last modified February 4 11:10 EST 2023. Contains 360055 sequences. (Running on oeis4.)