a(n) = Sum_{k=1..n} Sum_{z=1..n} Sum_{y=1..n} Sum_{x=1..n} [GCD(f(x,y,z), n) = k] * f(x,y,z) * A023900(k), where f(x,y,z) = x^2 + y^2 - z^2.

A373582

a(n) = Sum_{k=1..n} Sum_{z=1..n} Sum_{y=1..n} Sum_{x=1..n} [GCD(f(x,y,z), n) = k] * f(x,y,z) * A023900(k), where f(x,y,z) = x^2 + y^2 - z^2.

Terms

    a(0) =1a(1) =0a(2) =-117a(3) =0a(4) =-350a(5) =0a(6) =-4263a(7) =0a(8) =-7533a(9) =0a(10) =-27225a(11) =0a(12) =-17914a(13) =0a(14) =62100a(15) =0a(16) =-53176a(17) =0a(18) =-250173a(19) =0a(20) =83790a(21) =0a(22) =-541167a(23) =0a(24) =-168750a(25) =0a(26) =-557685a(27) =0a(28) =-459186a(29) =0

External references