case of n = 1 handled separately
if ( $ n == 1 ) echo " - 1 STRNEWLINE " ; else { $ b = ( $ n * $ n - 1 ) / 2 ; $ c = ( $ n * $ n + 1 ) / 2 ; echo " Side ▁ b ▁ = ▁ " . $ b . " , ▁ Side ▁ c ▁ = ▁ " . $ c . " STRNEWLINE " ; } } else {