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A153211
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Sum of digits of n, times digital reversal of sum of digits of n.
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1
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1, 4, 9, 16, 25, 36, 49, 64, 81, 1, 4, 9, 16, 25, 36, 49, 64, 81, 10, 4, 9, 16, 25, 36, 49, 64, 81, 10, 121, 9, 16, 25, 36, 49, 64, 81, 10, 121, 252, 16, 25, 36, 49, 64, 81, 10, 121, 252, 403, 25, 36, 49, 64, 81, 10, 121, 252, 403, 574, 36, 49, 64, 81, 10, 121, 252, 403, 574
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OFFSET
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1,2
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COMMENTS
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The fixed points of this sequence {n such that a(n) = n} are A110921.
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LINKS
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FORMULA
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EXAMPLE
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a(19) = (1+9)*R(1+9) = 10*01 = 10*1 = 10. a(79) = 976 because (7+9)*R(7+9) = 16*61 = 976.
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MATHEMATICA
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Table[With[{ds=Total[IntegerDigits[n]]}, IntegerReverse[ds]ds], {n, 70}] (* Harvey P. Dale, Mar 07 2023 *)
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CROSSREFS
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KEYWORD
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base,easy,nonn
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AUTHOR
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STATUS
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approved
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