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A200207
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Number of -n..n arrays x(0..5) of 6 elements with zero sum and nonzero second and third differences
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1
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50, 1042, 6418, 24542, 70400, 168054, 352840, 672632, 1191380, 1990668, 3169582, 4851400, 7182342, 10332674, 14504130, 19925886, 26858060, 35599134, 46482708, 59877540, 76196440, 95896240, 119471266, 147472836, 180499346, 219187302
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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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FORMULA
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Empirical: a(n) = -a(n-1) -2*a(n-2) -2*a(n-3) -3*a(n-4) -2*a(n-5) -2*a(n-6) +3*a(n-9) +3*a(n-10) +6*a(n-11) +5*a(n-12) +7*a(n-13) +5*a(n-14) +7*a(n-15) +3*a(n-16) +5*a(n-17) +a(n-18) +3*a(n-19) -a(n-20) +a(n-21) -3*a(n-22) -a(n-23) -6*a(n-24) -4*a(n-25) -10*a(n-26) -8*a(n-27) -13*a(n-28) -11*a(n-29) -14*a(n-30) -10*a(n-31) -12*a(n-32) -6*a(n-33) -6*a(n-34) +a(n-36) +6*a(n-37) +7*a(n-38) +10*a(n-39) +10*a(n-40) +12*a(n-41) +11*a(n-42) +12*a(n-43) +12*a(n-44) +11*a(n-45) +12*a(n-46) +10*a(n-47) +10*a(n-48) +7*a(n-49) +6*a(n-50) +a(n-51) -6*a(n-53) -6*a(n-54) -12*a(n-55) -10*a(n-56) -14*a(n-57) -11*a(n-58) -13*a(n-59) -8*a(n-60) -10*a(n-61) -4*a(n-62) -6*a(n-63) -a(n-64) -3*a(n-65) +a(n-66) -a(n-67) +3*a(n-68) +a(n-69) +5*a(n-70) +3*a(n-71) +7*a(n-72) +5*a(n-73) +7*a(n-74) +5*a(n-75) +6*a(n-76) +3*a(n-77) +3*a(n-78) -2*a(n-81) -2*a(n-82) -3*a(n-83) -2*a(n-84) -2*a(n-85) -a(n-86) -a(n-87)
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EXAMPLE
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Some solutions for n=3
.-3....0...-2...-1....0...-3...-3....3....0...-2...-3...-1...-1....0...-2....3
.-3....1....3...-1....1...-2...-2....0...-1....2....2...-1...-3....1....1...-2
..2....1....2....3....3....1....1...-1....2...-3...-2....3....3....0....3....3
..0....3...-2...-2...-3....3....1....2....0...-1....3...-2...-2....1...-3....1
..2...-3....0...-1...-2....1....0...-3....1....2....3....3....1...-3....0...-3
..2...-2...-1....2....1....0....3...-1...-2....2...-3...-2....2....1....1...-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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