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A165893
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Numbers n with property that n(n+2)(n+4) is a triangular number.
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1
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OFFSET
| 1,3
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COMMENTS
| Abscissas of integral points on the elliptic curve: m^2 = 8*n^3 + 48*n^2 + 64*n + 1.
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MATHEMATICA
| TNQ[n_]:=IntegerQ[Sqrt[1+8n]]; Select[Range[7500], TNQ[ #(#+2)(#+4)]&]
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CROSSREFS
| Cf. A001219 Triangular numbers of form a(a+1)(a+2), A165892 Triangular numbers of form a(a+2)(a+4).
Sequence in context: A122023 A179234 A009183 * A106397 A098150 A167375
Adjacent sequences: A165890 A165891 A165892 * A165894 A165895 A165896
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KEYWORD
| nonn,fini,full
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AUTHOR
| Zak Seidov (zakseidov(AT)yahoo.com), Sep 29 2009
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EXTENSIONS
| fini, full keywords from Max Alekseyev (maxale(AT)gmail.com), Oct 01 2009
Initial 0 added by Zak Seidov (zakseidov(AT)yahoo.com), Oct 04 2009 at the suggestion of Alexander R. Povolotsky.
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