Pandigital prime Problem 41 We shall say that an n-digit number is pandigital if it makes use of all the digits 1 to n exactly once. For example, 2143 ...
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其他好文 时间：
2018-01-24 13:55:17
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151
华电北风吹 天津大学认知计算与应用重点实验室 完毕日期：2015/7/29 Double-base palindromes Problem 36 The decimal number, 585 = 10010010012 (binary), is palindromic in both bases. ...
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2017-07-01 15:25:35
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134
Coded triangle numbers Problem 42 The nth term of the sequence of triangle numbers is given by, tn = ½n(n+1); so the first ten triangle numbers are: 1 ...
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2017-06-22 13:26:53
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153
Distinct primes factors
Problem 47
The first two consecutive numbers to have two distinct prime factors are:14 = 2 × 7
15 = 3 × 5The first three consecutive numbers to have three distinct prime fact...
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2015-08-15 21:36:32
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233
Pandigital prime
Problem 41
We shall say that an n-digit number is pandigital if it makes use of all the digits 1 to n exactly once. For example, 2143 is a 4-digit pandigital and is also prime.
What...
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其他好文 时间：
2015-07-30 17:05:09
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154
Coded triangle numbers
Problem 42
The nth term of the sequence of triangle numbers is given by, tn = ½n(n+1); so the first ten triangle numbers are:1, 3, 6, 10, 15, 21, 28, 36, 45, 55, …By converting...
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2015-07-30 17:00:20
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117
Truncatable primes
Problem 37
The number 3797 has an interesting property. Being prime itself, it is possible to continuously remove digits from left to right, and remain prime at each stage: 3797, 7...
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2015-07-30 13:43:24
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148
Pandigital multiples
Problem 38
Take the number 192 and multiply it by each of 1, 2, and 3:192 × 1 = 192
192 × 2 = 384
192 × 3 = 576
By concatenating each product we get the 1 to 9 pandigital, 192...
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2015-07-30 13:37:00
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134
华电北风吹
天津大学认知计算与应用重点实验室
完成日期：2015/7/30Integer right triangles
Problem 39
If p is the perimeter of a right angle triangle with integral length sides, {a,b,c}, there are exactly three solutions for p...
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2015-07-30 13:31:14
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178
华电北风吹
天津大学认知计算与应用重点实验室
完成日期：2015/7/29Double-base palindromes
Problem 36
The decimal number, 585 = 10010010012 (binary), is palindromic in both bases.Find the sum of all numbers, less than one milli...
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其他好文 时间：
2015-07-30 00:50:29
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139
