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A179642 Product of exactly 5 primes, 3 of which are distinct. 11
120, 168, 180, 252, 264, 270, 280, 300, 312, 378, 396, 408, 440, 450, 456, 468, 520, 552, 588, 594, 612, 616, 680, 684, 696, 700, 702, 728, 744, 750, 760, 828, 882, 888, 918, 920, 945, 952, 980, 984, 1026, 1032, 1044, 1064, 1100, 1116, 1128, 1144, 1160 (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

EXAMPLE

120=2^3*3*5, 168=2^3*3*7, 180=2^2*3^2*5, 252=2^2*3^2*7, 264=2^3*3*11, 270=2*3^3*5

MATHEMATICA

f[n_]:=Sort[Last/@FactorInteger[n]]=={1, 1, 3} || Sort[Last/@FactorInteger[n]]=={1, 2, 2}; Select[Range[2000], f]

PROG

(PARI) list(lim)=my(v=List(), t); forprime(p=2, (lim\6)^(1/3), forprime(q=2, sqrt(lim\p^3), if(p==q, next); t=p^3*q; forprime(r=q+1, lim\t, if(p==r, next); listput(v, t*r)))); forprime(p=2, sqrt(lim\12), forprime(q=p+1, sqrt(lim\p^2\2), t=(p*q)^2; forprime(r=2, lim\t, if(p==r||q==r, next); listput(v, t*r)))); vecsort(Vec(v)) \\ Charles R Greathouse IV, Jul 19 2011

CROSSREFS

Union of A189975 and A179643.

Cf. A006881, A007304, A085986, A085987, A178739.

Sequence in context: A034291 A039602 A316835 * A099832 A111399 A030634

Adjacent sequences:  A179639 A179640 A179641 * A179643 A179644 A179645

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Jul 21 2010

STATUS

approved

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Last modified November 18 12:16 EST 2019. Contains 329261 sequences. (Running on oeis4.)