A025322 Numbers that are the sum of 3 nonzero squares in exactly 2 ways.

27, 33, 38, 41, 51, 57, 59, 62, 69, 74, 75, 77, 83, 90, 94, 98, 102, 105, 107, 108, 113, 117, 118, 121, 122, 123, 125, 132, 137, 138, 139, 141, 147, 152, 154, 155, 158, 164, 165, 170, 177, 178, 181, 187, 195, 197, 203, 204, 210, 211, 213, 214, 217, 218, 226, 228, 229, 236

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Links

• Robert Price, Table of n, a(n) for n = 1..418
• Index entries for sequences related to sums of squares
• Eric Weisstein's World of Mathematics, Square Number.

Crossrefs

Cf. A024796, A025427, A025322, A025323, A025324, A025325, A025326, A025327, A025328, A025329, A025330, A025331, A025332, A025333, A025334, A025335, A025336, A025337, A025338.

Programs

Mathematica

okQ[n_]:=Length[Select[PowersRepresentations[n,3,2],!MemberQ[ #,0]&]] ==2; Select[Range[250],okQ] (* Harvey P. Dale, Jul 25 2011 *)