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A154877
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Numbers that eventually reach the cycle 160-217-352 under "x -> sum of cubes of digits of x" (see A055012).
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6
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16, 22, 61, 79, 97, 106, 115, 127, 151, 160, 172, 202, 217, 220, 229, 235, 238, 253, 271, 283, 292, 325, 328, 352, 382, 388, 445, 454, 457, 475, 511, 523, 532, 544, 547, 574, 601, 610, 709, 712, 721, 745, 754, 790, 823, 832, 838, 883, 907, 922, 970, 1006
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OFFSET
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1,1
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COMMENTS
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All the numbers are of the form 3n+1.
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LINKS
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EXAMPLE
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Taking 79 as an example; 7^3+9^3=1072, 1^3+0^3+7^3+2^3=352, 3^3+5^3+2^3=160, 1^3+6^3+0^3=217, 2^3+1^3+7^3=352.
a(15)=229: 229 -> 2*2^3+9^3=745 -> 7^3+4^3+5^3+1=532 -> 5^3+3^3+2^3=160 -> 217 -> 352 -> 160 ... .
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MATHEMATICA
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okQ[n_]:=MemberQ[NestList[Total[IntegerDigits[#]^3]&, n, 20], 160]; Select[Range[1200], okQ] (* Harvey P. Dale, Jun 20 2011 *)
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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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Avik Roy (avik_3.1416(AT)yahoo.co.in), Jan 16 2009
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EXTENSIONS
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Further terms added by Avik Roy (avik_3.1416(AT)yahoo.co.in), Jan 20 2009
Entry revised by N. J. A. Sloane, Oct 13 2018 (merging older duplicate entry with this one).
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STATUS
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approved
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