Create a boolean array " prime [ 0 . . n ] " and initialize all the entries as true . A value in prime [ i ] will finally be false if ' i ' is Not a prime , else true .
for ( int i = 0 ; i <= MAX ; i ++ ) prime [ i ] = true ; for ( int i = 0 ; i <= MAX ; i ++ ) sum [ i ] = 0 ; prime [ 1 ] = false ; for ( int p = 2 ; p * p <= MAX ; p ++ ) {