|
|
A211515
|
|
Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^3=x*y.
|
|
2
|
|
|
0, 1, 1, 1, 3, 3, 3, 3, 6, 8, 8, 8, 8, 8, 8, 8, 10, 10, 12, 12, 12, 12, 12, 12, 14, 16, 16, 21, 21, 21, 21, 21, 25, 25, 25, 25, 27, 27, 27, 27, 29, 29, 29, 29, 29, 29, 29, 29, 31, 33, 35, 35, 35, 35, 39, 39, 41, 41, 41, 41, 41, 41, 41, 41, 48, 48, 48, 48, 48, 48, 48
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,5
|
|
COMMENTS
|
For a guide to related sequences, see A211422.
|
|
LINKS
|
|
|
FORMULA
|
|
|
MATHEMATICA
|
t[n_] := t[n] = Flatten[Table[w^3 - x*y, {w, 1, n}, {x, 1, n}, {y, 1, n}]]
c[n_] := Count[t[n], 0]
t = Table[c[n], {n, 0, 70}] (* A211515 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|