|
|
A212059
|
|
Number of (w,x,y,z) with all terms in {1,...,n} and w=x*y*z-1.
|
|
2
|
|
|
0, 0, 3, 9, 12, 21, 24, 34, 40, 49, 52, 70, 73, 82, 91, 106, 109, 127, 130, 148, 157, 166, 169, 199, 205, 214, 224, 242, 245, 272, 275, 296, 305, 314, 323, 359, 362, 371, 380, 410, 413, 440, 443, 461, 479, 488, 491, 536, 542, 560, 569, 587, 590, 620
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
COMMENTS
|
For a guide to related sequences, see A211795.
|
|
LINKS
|
|
|
MATHEMATICA
|
t = Compile[{{n, _Integer}}, Module[{s = 0},
(Do[If[w == x*y*z - 1, s = s + 1],
{w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]];
Map[t[#] &, Range[0, 60]] (* A212059 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|