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A379595 Numbers k for which A376900(k) = k.

%I A379595 #4 Jan 07 2025 10:21:33
%S A379595 0,385,386,387,390,392,404,405,406
%N A379595 Numbers k for which A376900(k) = k.
%C A379595 The primitive Pythagorean triples cause A376900(n) to grow slightly overproportionally in relation to n, apart from minor fluctuations. This is why this sequence is finite and full.
%H A379595 Felix Huber, <a href="/A379595/a379595.txt">Right Triangles belonging to A376900(k)=k</a>
%p A379595 A379595:=proc(k)
%p A379595    local a,p,q,v,m;
%p A379595    a:=0;
%p A379595    for p from 2 to evalf(sqrt(sqrt(2)*k+1)) do
%p A379595       for q from 1 to min(p-1,floor(k/(sqrt(2)*p))) do
%p A379595          if gcd(p,q)=1 and is(p+q,odd) then
%p A379595             v:=max(p^2-q^2,2*p*q);
%p A379595             m:=min(p^2-q^2,2*p*q)/v;
%p A379595             a:=a+floor(k/v*sqrt(m^2-2*m+2));
%p A379595          fi
%p A379595       od
%p A379595    od;
%p A379595    if a=k then
%p A379595       return k
%p A379595    fi
%p A379595 end proc;
%p A379595 seq(A379595(k),k=0..1000);
%Y A379595 Cf. A376900.
%K A379595 nonn,fini,full
%O A379595 1,2
%A A379595 _Felix Huber_, Dec 26 2024