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A181721
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The smallest number k such that the product k*n contains digit-reverse(n) as a substring.
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3
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1, 1, 1, 1, 1, 1, 1, 1, 1, 101, 1, 18, 24, 101, 34, 101, 42, 45, 48, 51, 6, 1, 14, 101, 21, 24, 27, 65, 32, 101, 23, 72, 1, 101, 101, 101, 29, 22, 24, 26, 28, 22, 8, 1, 12, 14, 42, 8, 6, 21, 3, 49, 67, 27, 1, 101, 75, 32, 5, 51
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OFFSET
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1,10
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COMMENTS
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Here, the digit-reverse operation is defined to preserve trailing zeros: for n=10, digit-reverse(n) = 01 which is a substring of 101*10=1010, so a(10)=101. - R. J. Mathar, Nov 17 2010
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LINKS
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FORMULA
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MAPLE
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A181721 := proc(n) nrev := ListTools[Reverse](convert(n, base, 10)) ; for k from 1 do dgskn := convert(k*n, base, 10) ; if verify(nrev, dgskn, sublist) then return k; end if; end do: end proc:
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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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