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A112423
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Number of 6-element subsets of {1,2,3,...,n} which have a sum-set with 14 elements.
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1
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6, 24, 42, 60, 78, 96, 114, 138, 162, 198, 234, 270, 306, 342, 384, 426, 468, 522, 576, 630, 684, 744, 804, 864, 924, 996, 1068, 1140, 1218, 1296, 1374, 1452, 1530, 1620, 1710, 1806, 1902, 1998, 2094, 2190, 2286, 2394
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OFFSET
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8,1
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LINKS
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Colin Barker, Table of n, a(n) for n = 8..1000
Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,0,1,0,-1,0,0,0,0,0,-1,1).
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FORMULA
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G.f.: 6*x^8/((1-x)^2*(1-x^7))+12*x^9/((1-x)^2*(1-x^8)).
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MATHEMATICA
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DeleteCases[#, 0] &@ CoefficientList[Series[6 x^8/((1 - x)^2 (1 - x^7)) + 12 x^9/((1 - x)^2 (1 - x^8)), {x, 0, 49}], x] (* Michael De Vlieger, Jan 10 2017 *)
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PROG
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(PARI) Vec(6*x^8*(1 +3*x +3*x^2 +3*x^3 +3*x^4 +3*x^5 +3*x^6 +3*x^7) / ((1 -x)^3*(1 +x)*(1 +x^2)*(1 +x^4)*(1 +x +x^2 +x^3 +x^4 +x^5 +x^6)) + O(x^60)) \\ Colin Barker, Jan 10 2017
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CROSSREFS
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Sequence in context: A061811 A252066 A031101 * A069541 A062768 A161333
Adjacent sequences: A112420 A112421 A112422 * A112424 A112425 A112426
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KEYWORD
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nonn,easy
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AUTHOR
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David S. Newman, Dec 10 2005
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EXTENSIONS
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Edited by Colin Barker, Jan 10 2017
a(11) corrected by Colin Barker, Jan 10 2017
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STATUS
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approved
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