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A124966
Numbers which can be expressed as the ordered sum of 3 squares in 2 or more different ways.
12
9, 17, 18, 25, 26, 27, 29, 33, 34, 36, 38, 41, 45, 49, 50, 51, 53, 54, 57, 59, 61, 62, 65, 66, 68, 69, 72, 73, 74, 75, 77, 81, 82, 83, 85, 86, 89, 90, 94, 97, 98, 99, 100, 101, 102, 104, 105, 106, 107, 108, 109, 110, 113, 114, 116, 117, 118, 121, 122, 123, 125, 126, 129
OFFSET
1,1
LINKS
FORMULA
Equals = A000027 - A094942 - A004215.
EXAMPLE
a(1)=9 because 9 = 3^2 + 0^2 + 0^2 or 2^2 + 2^2 + 1^2.
MATHEMATICA
Select[Range[129], Length@PowersRepresentations[#, 3, 2] >= 2 &] (* Ray Chandler, Oct 31 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Nov 14 2006
EXTENSIONS
Corrected and extended by Ray Chandler, Nov 30 2006
STATUS
approved