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A277497
Number of cryptarithms of the form x + y = z in base n for which no summand contains any letter more than once and which have at least one solution.
2
3, 49, 1020, 28666, 1099824, 57520786, 3882860433, 331811494082
OFFSET
2,1
COMMENTS
Two cryptarithms are the same if one may be obtained from the other by a process of replacing letters and 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.
EXAMPLE
In base 10, the classic SEND + MORE = MONEY has an 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 + AB = CAA is solvable, and is counted. There are exactly two solutions: (A = 1, B = 0, C = 2) and (A = 2, B = 0, C = 1).
CROSSREFS
Cf. A277496.
Sequence in context: A208935 A355882 A202534 * A173174 A302466 A303248
KEYWORD
nonn,base,hard,more
AUTHOR
Eric M. Schmidt, Oct 18 2016
STATUS
approved