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A057684
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Trajectory of 13 under the `13x+1' map.
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8
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13, 170, 85, 17, 222, 111, 37, 482, 241, 3134, 1567, 20372, 10186, 5093, 463, 6020, 3010, 1505, 301, 43, 560, 280, 140, 70, 35, 7, 1, 14, 7, 1, 14, 7, 1, 14, 7, 1, 14, 7, 1, 14, 7, 1, 14, 7, 1, 14, 7, 1, 14, 7, 1, 14, 7, 1, 14, 7, 1, 14, 7, 1, 14, 7
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| The `Px+1 map': if x is divisible by any prime < P then divide out these primes one at a time starting with the smallest; otherwise multiply x by P and add 1.
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MAPLE
| with(numtheory): a := proc(n, S, Q) option remember: local k; if n=0 then RETURN(S); fi: for k from 1 to Q do if a(n-1, S, Q) mod ithprime(k) = 0 then RETURN(a(n-1, S, Q)/ithprime(k)); fi: od: RETURN(ithprime(Q+1)*a(n-1, S, Q)+1) end; # run with S=13 and Q=5.
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CROSSREFS
| Cf. A057446, A057216, A057522, A057534, A057614. See also A033478, A057688, A057684, A057685, A057686, A057687, A057689, A057690, A057691.
Sequence in context: A176596 A176023 A067220 * A053153 A167254 A140455
Adjacent sequences: A057681 A057682 A057683 * A057685 A057686 A057687
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Oct 20 2000
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