Function to calculate sum of all the GCD pairs
sumOfGcdPairs ( ) ; $ N = 4 ; echo " Summation ▁ of ▁ " . $ N . " ▁ = ▁ " . $ result [ $ N ] . " STRNEWLINE " ; $ N = 12 ; echo " Summation ▁ of ▁ " . $ N . " ▁ = ▁ " . $ result [ $ N ] . " STRNEWLINE " ; $ N = 5000 ; echo " Summation ▁ of ▁ " . $ N . " ▁ = ▁ " . $ result [ $ N ] . " STRNEWLINE " ; ? >