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A188251 Number of arrangements of 5 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero 1

%I #5 Mar 31 2012 12:36:11

%S 12,120,548,1504,3292,6376,10564,17040,25436,36808,49556,68912,87804,

%T 113384,144644,180912,216044,267160,312404,377904,446588,519976,

%U 590420,696576,791164,898456,1016756,1159280,1278636,1460936,1598916,1784224

%N Number of arrangements of 5 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero

%C Row 3 of A188249

%H R. H. Hardin, <a href="/A188251/b188251.txt">Table of n, a(n) for n = 1..47</a>

%e Some solutions for n=4

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 25 2011

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Last modified February 26 14:46 EST 2024. Contains 370352 sequences. (Running on oeis4.)