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A212097 Number of (w,x,y,z) with all terms in {1,...,n} and w^3<x^3+y^3+z^3. 3

%I #9 Dec 04 2016 19:46:29

%S 0,1,15,72,221,536,1098,2028,3445,5502,8368,12234,17304,23794,31963,

%T 42089,54439,69332,87070,108013,132549,161043,193924,231550,274463,

%U 323023,377776,439254,507882,584329,669046,762686,865804,979052

%N Number of (w,x,y,z) with all terms in {1,...,n} and w^3<x^3+y^3+z^3.

%C a(n)+A212100(n)=4^n. For a guide to related sequences, see A211795.

%t t = Compile[{{n, _Integer}}, Module[{s = 0},

%t (Do[If[w^3 < x^3 + y^3 + z^3, s = s + 1],

%t {w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]];

%t Map[t[#] &, Range[0, 40]] (* A212097 *)

%t (* _Peter J. C. Moses_, Apr 13 2012 *)

%Y Cf. A211795.

%K nonn

%O 0,3

%A _Clark Kimberling_, May 03 2012

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Last modified July 18 18:59 EDT 2024. Contains 374388 sequences. (Running on oeis4.)