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A364752
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Number of subsets of {1..n} containing n and all first differences.
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4
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1, 1, 2, 2, 4, 4, 9, 11, 24, 38, 75, 131, 263, 476, 928, 1750, 3386, 6439, 12455, 23853, 46097, 88709, 171471, 330939, 640472, 1238755, 2400154, 4650857, 9022792, 17510820, 34015138, 66106492, 128571563, 250191929, 487175381, 949133736, 1850223956, 3608650389
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OFFSET
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0,3
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LINKS
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EXAMPLE
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The a(1) = 1 through a(6) = 9 subsets:
{1} {2} {3} {4} {5} {6}
{1,2} {1,2,3} {2,4} {1,2,3,5} {3,6}
{1,2,4} {1,2,4,5} {2,4,6}
{1,2,3,4} {1,2,3,4,5} {1,2,3,6}
{1,2,4,6}
{1,2,3,4,6}
{1,2,3,5,6}
{1,2,4,5,6}
{1,2,3,4,5,6}
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MATHEMATICA
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Table[If[n==0, 1, Length[Select[Subsets[Range[n]], MemberQ[#, n]&&SubsetQ[#, Differences[#]]&]]], {n, 0, 10}]
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CROSSREFS
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The complement is counted by A364753.
A054519 counts subsets containing differences, A326083 containing sums.
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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