11 + 15 = 26.......iron......instability........2/6 = 1/3......the 2nd fraction........and the 3rd term of the harmonic series.....fractal patterns galore..........3.1415......the 5th number of pi is 5........1, 1, 2, 3, 5.....the 5th number of the Fibonacci sequence is also 5.......the power of 5...............


2, 3, 5, 7
2, 4, 6, 8.......6 and 8......the last 2 single digit even numbers...................adding straight down.......4, 7........11 and 15..........47......the 1st 10 numbers of e sum to 47.............which sums to 11....adding 4 + 7.........its single digit to its double digit.......also like 11/10 from Euler's product.......