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A140875
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Triangle read by rows: T(n,m) = gcd(n,m+2) - 2*gcd(n,m+1) - gcd(n,m), with diagonal and subdiagonal removed.
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0
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-2, -4, 0, -4, -4, 0, -6, -2, -2, 2, -6, -2, -6, -6, 2, -8, -2, -2, -2, -2, 4, -8, -4, 0, -8, -4, -4, 4, -10, 0, -6, -4, 0, -6, -4, 6, -10, -4, -2, 0, -10, -8, -2, -4, 6, -12, -2, -2, -2, -2, -2, -2, -2, -2, 8, -12, -2, -4, -10, 0, -12, -4, -6, -8, -6, 8, -14, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, 10
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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LINKS
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EXAMPLE
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{ -2},
{ -4, 0},
{ -4, -4, 0},
{ -6, -2, -2, 2},
{ -6, -2, -6, -6, 2},
{ -8, -2, -2, -2, -2, 4},
{ -8, -4, 0, -8, -4, -4, 4},
{-10, 0, -6, -4, 0, -6, -4, 6},
{-10, -4, -2, 0, -10, -8, -2, -4, 6}
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MATHEMATICA
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G[n_, m_] := GCD[n, m]
D2[n_, m_] := If[m + 2 <= n, G[n, m + 2] - 2*G[n, m + 1] - G[n, m], {} ];
a = Table[Flatten[Table[D2[n, m], {m, 0, n}]], {n, 0, 10}]; Flatten[a]
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CROSSREFS
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KEYWORD
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AUTHOR
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EXTENSIONS
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Definition corrected and more terms from Georg Fischer, Jun 08 2023
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STATUS
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approved
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