1 5 2n 2 3 3n July 8, 2019 16 32 64 128 Lim 3n 1 )/( 2n 5 )= 3 2 3 * 5 2n 1 2 3n 1 is divisible by 17 1 3 5 2n 1 3n 2 4 1 + 3 + 5 + . . . + (2n − 1) = n 2
