A211917 - OEIS

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A211917

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

0, 1, 15, 67, 210, 507, 1029, 1904, 3225, 5123, 7785, 11368, 16023, 22035, 29572, 38867, 50233, 63931, 80180, 99459, 121947, 148024, 178141, 212635, 251805, 296268, 346348, 402462, 465175, 534990, 612224, 697732, 791813, 895043

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

COMMENTS

a(n)+A211919(n)=n^4.

See A211795 for a guide to related sequences.

LINKS

Table of n, a(n) for n=0..33.

MATHEMATICA

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

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

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