21
21 = 3 * 7, F8 8th Fibonacci number
221 - 1 = 7 * 7 * 127 * 337
21 = 4!− 4 + 4 ÷ 4 = (44 − √4) ÷ √4
1021 - 1 = 3 * 3 * 3 * 37 * 43 * 239 * 1933 * 4649 * 10838689
Undergraduate Texts in Mathematics
Graduate Studies in Mathematics
21
21
21 = 3 * 7, F8 8th Fibonacci number
221 - 1 = 7 * 7 * 127 * 337
21 = 4!− 4 + 4 ÷ 4 = (44 − √4) ÷ √4
1021 - 1 = 3 * 3 * 3 * 37 * 43 * 239 * 1933 * 4649 * 10838689
Undergraduate Texts in Mathematics
Graduate Studies in Mathematics