OFFSET
0,2
COMMENTS
REFERENCES
See A025052
LINKS
Robert Israel, Table of n, a(n) for n = 0..826
EXAMPLE
a(2) = 23 because 23 is the least number with 2 representations: (a,b,c) = (1,2,7) and (1,3,5).
MAPLE
f:= proc(n) local a, t, s;
t:= 0;
for a from 1 to floor(sqrt(n/3)) do
t:= t + nops(select(s -> s > 2*a and n+a^2 > s^2, numtheory:-divisors(n+a^2)))
od;
t
end proc:
N:= 200: # for a(0)..a(N)
V:= Array(0..N): count:= 0:
for n from 1 while count < N+1 do
v:= f(n); if v <= N and V[v] = 0 then
count:= count+1; V[v]:= n; fi
od:
seq(V[i], i=0..N); # Robert Israel, May 05 2021
MATHEMATICA
cntMax=10; nSol=Table[{0, 0, 0}, {cntMax+1}]; Do[lim=Ceiling[(n-2)/3]; cnt=0; Do[If[n>a*b && Mod[n-a*b, a+b]==0 && Quotient[n-a*b, a+b]>b, cnt++; If[cnt>cntMax, Break[]]], {a, 1, lim-1}, {b, a+1, lim}]; If[cnt<=cntMax, If[nSol[[cnt+1, 1]]==0, nSol[[cnt+1, 1]]=n]; nSol[[cnt+1, 2]]=n; nSol[[cnt+1, 3]]++; ], {n, 10000}]; Table[nSol[[i, 1]], {i, cntMax+1}]
CROSSREFS
KEYWORD
nonn
AUTHOR
T. D. Noe and Robert G. Wilson v, Apr 28 2004
STATUS
approved