N 4 9 2 July 8, 2019 16 32 64 128 N 4 9 2 3 N 4 6 ) 2 9 1 4 9 n 2 1 4 9 16 n 2 formula 1 4 9 16 n 2 formula proof 4 n 9 2 7 N 4 2n 9 4 n 9 2 7 proportion 4 n 9 20 N 4 10n 2 9 N 4 9 n 8 2 Solve n 4 /- 2 =- 9 4 9 n 288 8n 4 )( n 2 9
