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A325450
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Numbers k such that sum of digits (k) and sum of digits (k^2) is 9.
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1
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9, 18, 45, 90, 180, 351, 450, 900, 1800, 3510, 4500, 9000, 18000, 35100, 45000, 90000, 180000, 351000, 450000, 900000, 1800000, 3510000, 4500000, 9000000, 18000000
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OFFSET
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1,1
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COMMENTS
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A007953(A058369(n)) begins with 1, 9, 1, 9, 10, 9, 10, 10, 9, 18, ...; the 1's come from A011557, the 9's come from this sequence, the 10's come from A325451.
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LINKS
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EXAMPLE
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a(3) = 45 because 4+5 = 9, 45^2 = 2025, and 2+0+2+5 = 9.
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MATHEMATICA
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Select[Range[2 10^7], Total[IntegerDigits[#]]==9&& Total[IntegerDigits[#^2]]==9&]
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PROG
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(Magma) [n: n in [1..2*10^7] | &+Intseq(n^2) eq 9 and &+Intseq(n) eq 9];
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CROSSREFS
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Subsequence of A058369 (k and k^2 have same digit sum).
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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