A060275 At least two ordered triples of positive numbers have sum n and equal products.

13, 14, 16, 17, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83

Offset

1,1

Comments

Any two such triples are disjoint.

Complement appears to be {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 15, 18}. - Robert Israel, Feb 10 2015

Links

Table of n, a(n) for n=1..69.

Example

13=6+6+1=9+2+2, 6*6*1=9*2*2, so 13 is in the sequence.

Maple

N:= 100: # to get all entries <= N
for i from 1 to N do R[i]:= {} od:
A:= {}:
for a from 1 to floor(N/3) do
  for b from a to floor((N-a)/2) do
    for c from b to N-a-b do
       p:= a*b*c;
       s:= a+b+c;
       if member(p, R[s]) then A:= A union {s}
       else R[s]:= R[s] union {p}
       fi;
od od od:
A;
# if using Maple 11 or earlier, uncomment the next line
# sort(convert(A, list));  # Robert Israel, Feb 10 2015

Crossrefs

Sequence in context: A346657 A171492 A054031 * A083984 A272022 A079495

Adjacent sequences: A060272 A060273 A060274 * A060276 A060277 A060278

Keyword

easy,nonn

Author

Naohiro Nomoto, Mar 23 2001

Extensions

Name changed by Robert Israel, Feb 12 2015

Status

approved