A124970 Smallest positive integer which can be expressed as the ordered sum of 3 squares in exactly n different ways.

7, 1, 9, 41, 81, 146, 194, 306, 369, 425, 594, 689, 866, 1109, 1161, 1154, 1361, 1634, 1781, 1889, 2141, 2729, 2609, 3626, 3366, 3566, 3449, 3506, 4241, 4289, 4826, 5066, 5381, 7034, 5561, 6254, 7229, 7829, 8186, 8069, 8126, 8609, 8921, 8774, 10386, 11574, 11129

Offset: 0

Author

Artur Jasinski, Nov 14 2006, Nov 20 2006

Keywords

• nonn

Links

• Michael S. Branicky, Table of n, a(n) for n = 0..2102

Crossrefs

Cf. A000451, A095809, A000437, A122699, A124966-A124971.

Programs

Mathematica

f[n_] := Block[{k = 1}, While[Length@PowersRepresentations[k, 3, 2] != n, k++]; k]; Table[f[n], {n, 0, 44}] (* Ray Chandler, Oct 31 2019 *)

Python

from collections import Counter
from itertools import count, combinations_with_replacement as mc
def aupto(lim):
  sq = filter(lambda x: x<=lim, (i**2 for i in range(int(lim**(1/2))+2)))
  s3 = filter(lambda x: 0Michael S. Branicky, Jul 01 2021

Extensions

Extended by Ray Chandler, Nov 30 2006

a(45) and beyond from Michael S. Branicky, Jul 01 2021