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A104347
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a(n) is the number of integers m such that (digit reversal of m) - m = 9*n.
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2
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8, 7, 6, 5, 4, 3, 2, 1, 0, 81, 80, 0, 0, 0, 0, 0, 0, 0, 0, 72, 8, 70, 0, 0, 0, 0, 0, 0, 0, 63, 16, 0, 60, 0, 0, 0, 0, 0, 0, 54, 24, 0, 0, 50, 0, 0, 0, 0, 0, 45, 32, 0, 0, 0, 40, 0, 0, 0, 0, 36, 40, 0, 0, 0, 0, 30, 0, 0, 0, 27, 48, 0, 0, 0, 0, 0, 20, 0, 0, 18, 56, 0, 0, 0, 0, 0, 0, 10, 0, 9, 64, 0, 0, 0
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OFFSET
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1,1
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COMMENTS
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For any n>0, a(n) is finite (or zero) and a(0) is infinite (because there are an infinite number of palindromes).
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LINKS
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EXAMPLE
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a(7)=2 because there are only two integers m such that (digit reversal of m) - m = 9*7=63, namely 18 and 29: 81-18=63 and 92-29=63.
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MATHEMATICA
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A104347=Table[Select[Range[0, 40000], (FromDigits[Reverse[IntegerDigits[ # ]]]-#)/9==k&]//Length, {k, 100}]
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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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