OFFSET
0,2
EXAMPLE
a(1) = 3 as 3 = 1 + 1 + 1 and 1 * 1 * 1 = 1 is a perfect cube.
MAPLE
N:= 2*10^4: m:= 67:
V:= Array(1..N): count:= 0:
for x from 1 to N/3 do
for y from x to (N-x)/2 do
F:= ifactors(x*y)[2];
b:= mul(t[1], t = select(s -> s[2] mod 3 = 2, F));
c:= mul(t[1], t = select(s -> s[2] mod 3 = 1, F));
for m from ceil((y/(b*c^2))^(1/3)) do
s:= x+y+m^3 * b * c^2;
if s > N then break fi;
if s < x + 2*y then next fi;
V[s]:= V[s]+1
od od od:
A:= Array(0..m): A[0]:= 1: count:= 1:
for i from 1 to N while count < m+1 do
v:= V[i];
if A[v] = 0 then A[v]:= i; count:= count+1 fi
od:
convert(V, list); # Robert Israel, Oct 21 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
David A. Corneth, Aug 21 2024
STATUS
approved