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A072588
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Numbers having at least one prime factor with an odd and one with an even exponent.
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2
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12, 18, 20, 28, 44, 45, 48, 50, 52, 60, 63, 68, 72, 75, 76, 80, 84, 90, 92, 98, 99, 108, 112, 116, 117, 124, 126, 132, 140, 147, 148, 150, 153, 156, 162, 164, 171, 172, 175, 176, 180, 188, 192, 198, 200, 204, 207, 208, 212, 220, 228, 234, 236, 240, 242, 244
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OFFSET
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1,1
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COMMENTS
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= Complement(Union(A002035, A000290)) = Intersection(A000037, A072587);
a(k)=A070011(k) for 0<k<=25, A070011(26)=120 is not a term, as 120=5*3*2^3 having only odd exponents (A002035(85)=120),
and a(54)=240 is not a term of A070011, as from 240=5*3*2^4 follows that A001222(240)/A001221(240)=6/3=2 is an integer.
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LINKS
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_Reinhard Zumkeller_, Table of n, a(n) for n = 1..10000
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PROG
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(Haskell)
a072588 n = a072588_list !! (n-1)
a072588_list = filter f [1..] where
f x = any odd es && any even es where es = a124010_row x
-- Reinhard Zumkeller, Nov 15 2012
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CROSSREFS
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Cf. A124010.
Sequence in context: A162947 A070011 A084679 * A187039 A072357 A054753
Adjacent sequences: A072585 A072586 A072587 * A072589 A072590 A072591
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KEYWORD
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nonn
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AUTHOR
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Reinhard Zumkeller, Jun 23 2002
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STATUS
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approved
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