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A003595
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Numbers of the form 5^i*7^j with i, j >= 0.
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12
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1, 5, 7, 25, 35, 49, 125, 175, 245, 343, 625, 875, 1225, 1715, 2401, 3125, 4375, 6125, 8575, 12005, 15625, 16807, 21875, 30625, 42875, 60025, 78125, 84035, 109375, 117649, 153125, 214375, 300125, 390625, 420175, 546875, 588245, 765625, 823543, 1071875, 1500625
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OFFSET
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1,2
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COMMENTS
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Successive k such that EulerPhi[35 k] = 24 k: 35*A003595(n)=A033851(n). [Artur Jasinski, Nov 09 2008]
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LINKS
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Alois P. Heinz, Table of n, a(n) for n = 1..1000
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MATHEMATICA
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a = {}; Do[If[EulerPhi[35 k] == 24 k, AppendTo[a, k]], {k, 1, 10000}]; a (* Artur Jasinski, Nov 09 2008 *)
fQ[n_] := PowerMod[35, n, n] == 0; Select[Range[600000], fQ] (* Bruno Berselli, Sep 24 2012 *)
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PROG
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(PARI) list(lim)=my(v=List(), N); for(n=0, log(lim)\log(7), N=7^n; while(N<=lim, listput(v, N); N*=5)); vecsort(Vec(v)) \\ Charles R Greathouse IV, Jun 28 2011
(MAGMA) [n: n in [1..600000] | PrimeDivisors(n) subset [5, 7]]; // Bruno Berselli, Sep 24 2012
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CROSSREFS
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Cf. A033851, A143207, A147571-A147580.
Sequence in context: A072370 A057490 A057253 * A018697 A018319 A100095
Adjacent sequences: A003592 A003593 A003594 * A003596 A003597 A003598
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KEYWORD
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nonn,changed
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AUTHOR
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N. J. A. Sloane.
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STATUS
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approved
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