

A229140


Smallest k such that k^2 + l^2 = nth number expressible as sum of two squares (A001481).


0



0, 0, 1, 0, 1, 2, 0, 1, 2, 0, 1, 3, 2, 0, 1, 2, 4, 3, 0, 1, 2, 4, 3, 0, 1, 4, 2, 3, 5, 0, 1, 2, 6, 3, 5, 4, 0, 1, 2, 5, 3, 4, 7, 0, 1, 2, 5, 3, 7, 4, 6, 0, 1, 2, 8, 3, 6, 4, 0, 1, 5, 2, 7, 3, 6, 4, 9, 8, 0, 1, 2, 3, 6, 9, 4, 7, 5, 0, 1, 2, 9, 3, 8, 4, 7, 5, 0
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OFFSET

1,6


COMMENTS

a(n) = 0 if A001481(n) is square. Conjecture: the values between two zeros are always distinct from each other.


LINKS



EXAMPLE

The 6th number expressible as sum of two squares A001481(6) = 8 = 2^2 + 2^2, so a(6)=2.


PROG

(PARI) for(n=1, 300, s=sqrtint(n); forstep(i=s, 1, 1, if(issquare(ni*i), print1(sqrtint(ni*i), ", "); break)))


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



