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A179298
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a(n)=n^3-(n-1)^3-(n-2)^3-...-1.
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0
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1, 7, 18, 28, 25, -9, -98, -272, -567, -1025, -1694, -2628, -3887, -5537, -7650, -10304, -13583, -17577, -22382, -28100, -34839, -42713, -51842, -62352, -74375, -88049, -103518, -120932, -140447, -162225, -186434, -213248, -242847, -275417
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OFFSET
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1,2
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COMMENTS
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1^3-0=1, 2^3-1=7, 3^3-2^3-1=18, 4^3-3^3-2^3-1=28, 5^3-4^3-3^3-2^3-1=25, 6^3-5^3-4^3-3^3-2^3-1=-9,..
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LINKS
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Table of n, a(n) for n=1..34.
Index to sequences with linear recurrences with constant coefficients, signature (5,-10,10,-5,1). [From R. J. Mathar, Jul 11 2010]
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FORMULA
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a(n) = -n^2*(1-6*n+n^2)/4. G.f.: (2*x-1)*(x^2+4*x+1)/(x-1)^5. [From R. J. Mathar, Jul 11 2010]
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MATHEMATICA
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f[n_]:=Module[{k=n-1, x=n^3}, While[k>0, x-=k^3; k--; ]; x]; lst={}; Do[AppendTo[lst, f[n]], {n, 5!}]; lst
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CROSSREFS
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Cf. A173142, A179297
Sequence in context: A090098 A101865 A138391 * A144175 A131191 A017473
Adjacent sequences: A179295 A179296 A179297 * A179299 A179300 A179301
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KEYWORD
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sign,easy
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AUTHOR
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Vladimir Joseph Stephan Orlovsky, Jul 09 2010
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STATUS
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approved
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