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A382297 Indices of right triangles in A381337.

%I A382297 #7 Mar 29 2025 18:37:44
%S A382297 1,2,3,4,6,7,12,14,17,23,28,31,34,35,49,51,62,69,71,73,77,85,93,97,98,
%T A382297 102,119,127,142,161,170,194,196,199,223,233,238,241,245,279,281,287,
%U A382297 291,337,357,381,388,391,398,439,446,449,476,482,483,511,521,527,562
%N A382297 Indices of right triangles in A381337.
%C A382297 A381336(a(n)) is the short leg, a(n) + A381336(a(n)) is the long leg and A381337(a(n)) is the hypotenuse.
%F A382297 A381336(a(n))^2 + (A381336(a(n)) + a(n))^2 = A381337(a(n))^2.
%e A382297 12 is in the sequence because A381336(12)^2 + (A381336(12) + 12)^2 = 36^2 + 48^2 = 60^2 = A381337(12)^2.
%p A382297 isA382297:=proc(n)
%p A382297     local k,c,s;
%p A382297     for k do
%p A382297         for c from k+n to 2*k+n-1 do
%p A382297             s:=(n+2*k+c)/2;
%p A382297             if issqr(s*(s-k)*(s-k-n)*(s-c)) then
%p A382297                 return [k,n+k,c];
%p A382297             fi
%p A382297         od
%p A382297     od;
%p A382297 end proc;
%p A382297 A382297:=proc(n)
%p A382297     option remember;
%p A382297     local a;
%p A382297     if n=1 then
%p A382297         1
%p A382297     else
%p A382297         for a from procname(n-1)+1 do
%p A382297             if isA382297(a)[1]^2+isA382297(a)[2]^2=isA382297(a)[3]^2 then
%p A382297                 return a
%p A382297             fi
%p A382297         od
%p A382297     fi;
%p A382297 end proc;
%p A382297 seq(A382297(n),n=1..59);
%Y A382297 Cf. A381336, A381337.
%K A382297 nonn
%O A382297 1,2
%A A382297 _Felix Huber_, Mar 26 2025