7 is the sole selection D for which the equation 2n ? D = x2 has in excess of two answers for n and x natural. Specifically, the equation 2n ? seven = x2 is known as the Ramanujan–Nagell equation.Not surprisingly There's also the very well-known Tale of Pharaohs desire concerning the 7 Body fat cows and seven skinny cows.You can go from a rap mus… Read More