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A190379 Numbers with prime factorization pqr^2s^2t^2. 2
69300, 81900, 97020, 107100, 114660, 119700, 128700, 144900, 149940, 152460, 161700, 167580, 168300, 182700, 188100, 191100, 195300, 198900, 202860, 212940, 222300, 227700, 233100, 242550, 249900, 252252, 254100, 255780, 258300, 269100 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000

Will Nicholes, Prime Signatures

Index to sequences related to prime signature

MATHEMATICA

f[n_]:=Sort[Last/@FactorInteger[n]]=={1, 1, 2, 2, 2}; Select[Range[600000], f]

PROG

(PARI) list(lim)=my(v=List(), t1, t2, t3, t4); forprime(p=2, sqrtint(lim\1260), t1=p^2; forprime(q=2, sqrtint(lim\(60*t1)), if(q==p, next); t2=q^2*t1; forprime(r=2, sqrtint(lim\(6*t2)), if(r==p || r==q, next); t3=r^2*t2; forprime(s=2, lim\(2*t3), if(s==p || s==q || s==r, next); t4=s*t3; forprime(t=2, lim\t4, if(t==p || t==q || t==r || t==s, next); listput(v, t4*t)))))); Set(v) \\ Charles R Greathouse IV, Aug 25 2016

CROSSREFS

Cf. A190110, A190111.

Sequence in context: A096552 A031663 A105010 * A205758 A205588 A162874

Adjacent sequences:  A190376 A190377 A190378 * A190380 A190381 A190382

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, May 09 2011

STATUS

approved

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Last modified January 20 14:17 EST 2021. Contains 340302 sequences. (Running on oeis4.)