7
7 = 4 + 4 − 4 ÷ 4 = 44 ÷ 4 − 4
27 - 1 = 127, Prime number
Undergraduate Texts in Mathematics
Graduate Studies in Mathematics
7
7
7 = 4 + 4 − 4 ÷ 4 = 44 ÷ 4 − 4
27 - 1 = 127, Prime number
Undergraduate Texts in Mathematics
Graduate Studies in Mathematics