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A192699
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Number of 2X4 integer matrices with each row summing to zero, row elements in nondecreasing order, rows in lexicographically nondecreasing order, and the sum of squares of the elements <= 2*n^2 (number of collections of 2 zero-sum 4-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations)
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1
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2, 11, 48, 166, 459, 1125, 2426, 4871, 9028, 15919, 26530, 42795, 66234, 100066, 146708, 211012, 295903, 409009, 555042, 743702, 980297, 1279677, 1648401, 2106146, 2660304, 3336122, 4142715, 5114735, 6259510, 7619959, 9210010
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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Some solutions for 2X4 <= 2*4^2
.-3.-1..1..3...-3.-1..2..2...-1.-1..0..2...-2.-1..0..3...-2.-2..1..3
.-3..1..1..1...-2.-1..0..3....0..0..0..0...-2..0..0..2...-2..0..0..2
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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