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A076295
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Consider all Pythagorean triples (Y-7,Y,Z); sequence gives Y values.
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4
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4, 7, 12, 15, 28, 55, 72, 147, 304, 403, 840, 1755, 2332, 4879, 10212, 13575, 28420, 59503, 79104, 165627, 346792, 461035, 965328, 2021235, 2687092, 5626327, 11780604, 15661503, 32792620, 68662375, 91281912, 191129379, 400193632, 532029955, 1113983640
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OFFSET
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0,1
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COMMENTS
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First two terms included for consistency with A076293.
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LINKS
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FORMULA
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a(0)=4, a(1)=7, a(2)=12, a(3)=15, a(4)=28, a(5)=55, a(6)=72, a(n)= a(n-1)+ 6*a(n-3)-6*a(n-4)-a(n-6)+a (n-7). - Harvey P. Dale, Feb 02 2012
G.f.: -(3*x^6-3*x^5-5*x^4-21*x^3+5*x^2+3*x+4) / ((x-1)*(x^6-6*x^3+1)). - Colin Barker, Sep 14 2014
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EXAMPLE
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15 is in the sequence as the longer leg of the (8,15,17) triangle.
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MATHEMATICA
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LinearRecurrence[{1, 0, 6, -6, 0, -1, 1}, {4, 7, 12, 15, 28, 55, 72}, 40] (* Harvey P. Dale, Feb 02 2012 *)
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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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