sqrt(1)+sqrt(4) +sqrt(9)=1+2+3=6
sqrt(2)=1.41421356237309504880...
sqrt(3)=1.73205080756887729352...
sqrt(5)=2.23606797749978969405...
sqrt(6)=2.449489742783178098195
sqrt(7)=2.645751311064590590501615
sqrt(8)=2.828427124746190097603
this sum =13.306000526035720822670
add 6...19.306000526035720822670