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A189953 1/4 the number of arrangements of 4 nonzero numbers x(i) in -n..n with the sum of sign(x(i))*(|x(i)| mod x(i+1)) equal to zero 1
4, 22, 63, 159, 306, 542, 889, 1350, 1940, 2734, 3670, 4819, 6238, 7852, 9688, 11986, 14411, 17274, 20412, 23919, 27900, 32443, 37028, 42280, 48028, 54459, 60919, 68477, 76078, 84753, 93786, 103538, 113637, 125008, 136030, 149100, 162115, 176241 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 3 of A189951

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

EXAMPLE

Some solutions with n=3

..1....3....1....2...-2....2....3....1...-1....2...-3...-1...-3...-1....1....3

.-3...-3...-3...-2....2...-2....1....1...-1....2...-3....3....2....2...-2....3

.-3...-3....2...-2...-1....2...-3....1....1...-1...-3....2....1....1...-1...-3

..2....1...-2...-2...-1....2...-2....1...-1...-1...-1....2....3...-3....3...-1

CROSSREFS

Sequence in context: A104171 A036924 A130015 * A174814 A106846 A086863

Adjacent sequences:  A189950 A189951 A189952 * A189954 A189955 A189956

KEYWORD

nonn

AUTHOR

R. H. Hardin May 02 2011

STATUS

approved

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Last modified September 28 04:53 EDT 2021. Contains 347703 sequences. (Running on oeis4.)