a = {2,3,3,2};  b = {2,2,6,6};

1/2 Table[Det[{{a[[Mod[n,4,1]]],a[[Mod[n+1,4,1]]]},{b[[Mod[n,4,1]]],b[[Mod[n+1,4,1]]]}}],{n,1,4}]

Total[%]

?Mod

Table[Abs[Mod[n,4,1],{n,1,8}]

Take[Sort[Flatten[Table[{Abs[2006 - x^2 - y^7],x,y},{x,1,45},{y,1,13}],1]],20]

gg = Take[Union[Flatten[Table[x^y,{x,2,60},{y,2,30}]]],70]

Take[Reverse[Sort[Split[Sort[Flatten[Table[gg[[n]]+gg[[m]],{n,1,69},{m,n+1,70}]]]]]],300]

26^2 + 11^3

42^2 + 3^5

N[2006^(1/3)]