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A190380
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Numbers with prime factorization pqrst^2u^2.
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2
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180180, 235620, 263340, 278460, 300300, 311220, 318780, 376740, 392700, 401940, 406980, 420420, 429660, 437580, 438900, 450450, 464100, 475020, 489060, 492660, 507780, 512820, 518700, 531300, 549780, 550620, 568260, 589050, 592020, 595980
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OFFSET
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1,1
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LINKS
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T. D. Noe, Table of n, a(n) for n = 1..1000
Will Nicholes, Prime Signatures
Index to sequences related to prime signature
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MATHEMATICA
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f[n_]:=Sort[Last/@FactorInteger[n]]=={1, 1, 1, 1, 2, 2}; Select[Range[1000000], f]
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PROG
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(PARI) list(lim)=my(v=List(), t1, t2, t3, t4, t5); forprime(p=2, sqrtint(lim\4620), t1=p^2; forprime(q=2, sqrtint(lim\(210*t1)), if(q==p, next); t2=q^2*t1; forprime(r=2, lim\(30*t2), if(r==p || r==q, next); t3=r*t2; forprime(s=2, lim\(6*t3), if(s==p || s==q || s==r, next); t4=s*t3; forprime(t=2, lim\(2*t4), if(t==p || t==q || t==r || t==s, next); t5=t*t4; forprime(u=2, lim\t5, if(u==p || u==q || u==r || u==s || u==t, next); listput(v, t5*u))))))); Set(v) \\ Charles R Greathouse IV, Aug 25 2016
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CROSSREFS
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Cf. A190378, A190379.
Sequence in context: A258562 A204787 A060232 * A235716 A274365 A209828
Adjacent sequences: A190377 A190378 A190379 * A190381 A190382 A190383
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KEYWORD
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nonn
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AUTHOR
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Vladimir Joseph Stephan Orlovsky, May 09 2011
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STATUS
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approved
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