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 A179643 Products of exactly 2 distinct squares of primes and a different prime (p^2 * q^2 * r). 16
 180, 252, 300, 396, 450, 468, 588, 612, 684, 700, 828, 882, 980, 1044, 1100, 1116, 1300, 1332, 1452, 1476, 1548, 1575, 1692, 1700, 1900, 1908, 2028, 2124, 2156, 2178, 2196, 2205, 2300, 2412, 2420, 2450, 2475, 2548, 2556, 2628, 2844, 2900, 2925, 2988 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS A050326(a(n)) = 5, subsequence of A225228. - Reinhard Zumkeller, May 03 2013 LINKS T. D. Noe, Table of n, a(n) for n = 1..1000 Will Nicholes, Prime Signatures EXAMPLE 180 = 2^2 * 3^2 * 5, 252 = 2^2 * 3^2 * 7, 300 = 2^2 * 3 * 5^2, ... MATHEMATICA f[n_]:=Sort[Last/@FactorInteger[n]]=={1, 2, 2}; Select[Range[3000], f] PROG (PARI) list(lim)=my(v=List(), t); 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 Cf. A006881, A007304, A065036, A085986, A085987, A178739, A179642. Cf. A179695. Sequence in context: A291457 A289056 A030636 * A160134 A135193 A095650 Adjacent sequences:  A179640 A179641 A179642 * A179644 A179645 A179646 KEYWORD nonn AUTHOR Vladimir Joseph Stephan Orlovsky, Jul 21 2010 STATUS approved

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Last modified December 18 18:47 EST 2018. Contains 318243 sequences. (Running on oeis4.)