OFFSET
1,1
COMMENTS
These are the squares in A004432. - Omar E. Pol, Sep 18 2020
FORMULA
a(n) = A161992(n)^2. - Andrew Howroyd, Sep 18 2020
EXAMPLE
49 is a term because 6^2(36) + 3^2(9) + 2^2(4) = 7^2(49).
81 is a term because 8^2(64) + 4^2(16) + 1^2(1) = 9^2(81).
121 is a term because 9^2(81) + 6^2(36) + 2^2(4) = 11^2(121).
625 is a term because 9^2(81) + 12^2(144) + 20^2(400) = 25^2(625).
MATHEMATICA
Select[Range[63]^2, Length @ Reduce[x^2 + y^2 + z^2 == # && 0 < x < y < z, {x, y, z}, Integers] > 0 &] (* Amiram Eldar, Sep 18 2020 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Joseph Caliendo, Sep 18 2020
STATUS
approved