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 A075819 Even squarefree numbers with exactly 3 prime factors. 14
 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; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS This sequence first differs from A053858 at 2310=2*3*5*7*11, which is in A053858 but not in this sequence. LINKS Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 FORMULA a(n) = 2 * A046388(n). - Amiram Eldar, Mar 03 2021 EXAMPLE 30=2*3*5 and 42=2*3*7 are even, squarefree and have 3 prime factors. MAPLE ts_3_sod := proc(n); if (numtheory[bigomega](n)=3 and numtheory[mobius](n)=-1 and type(n, even)='true') then RETURN(n); fi end: a3sod := [seq(ts_3_sod(i), i=1..2500)]: a3sod; MATHEMATICA Select[2*Range[300], SquareFreeQ[#]&&PrimeNu[#]==3&] (* Harvey P. Dale, Feb 16 2018 *) PROG (PARI) list(lim)=my(v=List()); forprime(p=5, lim\6, forprime(q=3, min(lim\(2*p), p-2), listput(v, 2*p*q))); Set(v) \\ Charles R Greathouse IV, Aug 29 2017 CROSSREFS Cf. A046388, A053858. Sequence in context: A007304 A160350 A053858 * A306217 A034683 A328328 Adjacent sequences:  A075816 A075817 A075818 * A075820 A075821 A075822 KEYWORD easy,nonn AUTHOR Jani Melik, Oct 13 2002 EXTENSIONS Edited by Dean Hickerson, Oct 21 2002 STATUS approved

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Last modified April 20 06:59 EDT 2021. Contains 343125 sequences. (Running on oeis4.)