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A190111 Numbers with prime factorization p*q*r*s^2*t^3 (where p, q, r, s, t are distinct primes). 3
27720, 32760, 41580, 42840, 46200, 47880, 49140, 51480, 54600, 57960, 64260, 64680, 67320, 71400, 71820, 72072, 73080, 75240, 76440, 77220, 78120, 79560, 79800, 85800, 86940, 88920, 91080, 93240, 94248, 96600, 99960, 100980, 101640, 103320 (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

EXAMPLE

From Petros Hadjicostas, Oct 26 2019: (Start)

a(1) = (2^3)*(3^2)*5*7*11 = 27720;

a(2) = (2^3)*(3^2)*5*7*13 = 32760;

a(3) = (2^2)*(3^3)*5*7*11 = 41580;

a(4) = (2^3)*(3^2)*5*7*17 = 42840;

a(5) = (2^3)*3*(5^2)*7*11 = 46200.

(End)

MATHEMATICA

f[n_]:=Sort[Last/@FactorInteger[n]]=={1, 1, 1, 2, 3}; Select[Range[150000], f]

PROG

(PARI) list(lim)=my(v=List(), t1, t2, t3, t4); forprime(p=2, sqrtnint(lim\420, 3), t1=p^3; forprime(q=2, sqrtint(lim\(30*t1)), if(q==p, next); t2=q^2*t1; forprime(r=2, lim\(6*t2), if(r==p || r==q, next); t3=r*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. A179645, A189990, A190109, A190110.

Sequence in context: A023198 A230608 A204831 * A068404 A279091 A307114

Adjacent sequences:  A190108 A190109 A190110 * A190112 A190113 A190114

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, May 04 2011

STATUS

approved

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Last modified September 21 11:46 EDT 2020. Contains 337268 sequences. (Running on oeis4.)