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Search: id:A053858
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| A053858 |
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Even numbers n with an odd number of prime factors. |
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+0
4
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| 30, 42, 66, 70, 78, 102, 110, 114, 130, 138, 154, 170, 174, 182, 186, 190, 222, 230, 238, 246, 258, 266, 282, 286, 290, 310, 318, 322, 354, 366, 370, 374, 402, 406, 410, 418, 426, 430, 434, 438, 442, 470, 474, 494, 498, 506, 518, 530, 534, 574, 582, 590
(list; graph; listen)
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OFFSET
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1,1
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FORMULA
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Even numbers n where mu(n) = -1
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EXAMPLE
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a(3)=66 because 66 is even and prime divisors are 2, 3, and 11, an odd number.
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MAPLE
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ts_m2_sod := proc(n); if (numtheory[mobius](n)=-1 and isprime(n)='false' and type(n, even)='true') then RETURN(n); fi end: am2sod := [seq(ts_m2_sod(i), i=1..2500)]: am2sod;
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CROSSREFS
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A007304.
Adjacent sequences: A053855 A053856 A053857 this_sequence A053859 A053860 A053861
Sequence in context: A090815 A093599 A007304 this_sequence A075819 A034683 A087248
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KEYWORD
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easy,nonn
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AUTHOR
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Enoch Haga (Enokh(AT)comcast.net), Mar 28 2000
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