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A194041
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Lucky numbers which are also unhappy numbers.
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1
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3, 9, 15, 21, 25, 33, 37, 43, 51, 63, 67, 69, 73, 75, 87, 93, 99, 105, 111, 115, 127, 135, 141, 151, 159, 163, 169, 171, 189, 195, 201, 205, 211, 223, 231, 235, 237, 241, 259, 261, 267, 273, 283, 285, 289, 297, 303, 307, 321, 327, 339, 349, 357, 361, 385, 393
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OFFSET
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1,1
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COMMENTS
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An unhappy number is a number that is not happy (A007770) i.e., a number n such that iterating this sum-of-squared-digits map starting with n never reaches the number 1. Many asymptotic properties of the prime numbers are shared by the lucky numbers.
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LINKS
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FORMULA
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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