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A277496
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Number of cryptarithms of the form x + y = z in base n for which no summand contains any letter more than once and for which the solution is unique.
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2
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OFFSET
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2,1
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COMMENTS
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Two cryptarithms are the same if one may be obtained from the other by a process of replacing letters and/or swapping the summands. For instance, the problem AB + BCD = DDD is the same as ABC + DA = CCC.
Solutions must assign a different digit to each letter, and numbers may not begin with 0.
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LINKS
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EXAMPLE
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In base 10, the classic SEND + MORE = MONEY has a unique assignment of digits to the letters that makes the equation true, and is counted because neither SEND nor MORE contains a given letter more than once.
In base 3, CBA + CAB = AAA has a unique solution (A = 2, B = 0, C = 1), and so is counted.
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CROSSREFS
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KEYWORD
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nonn,base,hard,more
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AUTHOR
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STATUS
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approved
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