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A165892
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Triangular numbers of form n(n+2)(n+4).
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3
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OFFSET
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1,2
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COMMENTS
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Values of (m^2-1)/8 corresponding to ordinates of integral points on the elliptic curve: m^2 = 8*n^3 + 48*n^2 + 64*n + 1.
Corresponding values of n are given in A165893.
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LINKS
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MATHEMATICA
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TNQ[m_]:=IntegerQ[Sqrt[1+8*m]]; Do[If[TNQ[m=n*(n+2)*(n+4)], Print[m]], {n, 2*10^3}]
Select[Table[n(n+2)(n+4), {n, 0, 2000}], OddQ[Sqrt[8#+1]]&] (* Harvey P. Dale, Feb 07 2015 *)
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CROSSREFS
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Cf. A001219 Triangular numbers of form a(a+1)(a+2).
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KEYWORD
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nonn,fini,full
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AUTHOR
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EXTENSIONS
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Initial 0 added by Zak Seidov, Oct 04 2009 at the suggestion of Alexander R. Povolotsky.
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STATUS
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approved
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