Let be the digits of in decimal representation. Find the integer such that the following equation is true
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The number of digits in a number N (that is not a power of 10) is simply ⌈ lo g 1 0 N ⌉ . 1 0 1 A = ⌈ 1 0 1 1 lo g 1 0 2 0 1 8 2 0 1 8 ⌉ = ⌈ 1 0 1 2 0 1 8 lo g 1 0 ( 2 . 0 1 8 × 1 0 3 ) ⌉ = ⌈ 1 0 1 2 0 1 8 ( 3 + lo g 1 0 2 . 0 1 8 ) ⌉ ≈ ⌈ 2 0 ( 3 + lo g 1 0 2 ) ⌉ ≈ 6 0 + lo g 1 0 2 2 0 ≈ 6 0 + 6 = 6 6 Thus, we need k such that 2 k + 1 < 6 6 < 2 k + 3 and k = 3 2