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A256632
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a(n) = the smallest number k such that sigma(k) ends with the same concatenation of digits as n in base 10.
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1
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1, 6, 2, 3, 8, 5, 4, 7, 18, 104, 256, 6, 9, 13, 8, 102, 100, 10, 288, 19, 81, 146, 512, 14, 2928200, 68, 64, 12, 1089, 29, 16, 21, 121, 90, 6272, 22, 1600, 37, 18, 27, 441, 20, 722, 43, 1352, 180, 324, 33, 338, 149, 576, 96, 529, 34, 128, 28, 49, 157, 1058, 24
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OFFSET
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1,2
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LINKS
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EXAMPLE
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For n = 5, sigma(8) = 15, which ends in 5. The number 8 is the smallest number with this property so a(5) = 8.
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PROG
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(Magma) A256632:=func<n|exists(r){k:k in[1..10000000] | (SumOfDivisors(k)-n) mod 10^(#Intseq(n)) eq 0}select r else 0>; [A256632(n):n in[1..100]]
(PARI) a(n)=k=1; d=digits(n); while((sigma(k)-n)%(10^#d), k++); k
vector(50, n, a(n)) \\ Derek Orr, Apr 05 2015
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CROSSREFS
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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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