A212245 - OEIS

A212245

Number of (w,x,y,z) with all terms in {1,...,n} and w = x*y*z - 2*n.

0, 0, 0, 4, 12, 15, 21, 36, 45, 46, 64, 76, 88, 91, 114, 120, 144, 156, 153, 186, 204, 201, 235, 235, 268, 271, 289, 316, 334, 340, 361, 382, 408, 408, 444, 465, 465, 489, 519, 525, 576, 573, 589, 616, 652, 640, 664, 709, 736, 748, 760, 778, 826, 808

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OFFSET

0,4

COMMENTS

For a guide to related sequences, see A211795.

LINKS

Table of n, a(n) for n=0..53.

MATHEMATICA

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

(Do[If[w == x*y*z - 2 n, s = s + 1],

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

Map[t[#] &, Range[0, 60]] (* A212245 *)