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A179705 Numbers of the form p^7*q^3 where p and q are distinct primes. 3
3456, 16000, 17496, 43904, 170368, 273375, 281216, 625000, 628864, 750141, 877952, 1557376, 2109375, 2910897, 3121792, 3813248, 4804839, 6483584, 6588344, 8821888, 10176896, 10744731, 13289344, 15000633, 19056256 (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

MATHEMATICA

f[n_]:=Sort[Last/@FactorInteger[n]]=={3, 7}; Select[Range[100000], f]

With[{nn=25}, Take[Union[#[[1]]^7 #[[2]]^3&/@(Flatten[{#, Reverse[ #]}&/@ Subsets[ Prime[Range[nn]], {2}], 1])], nn]] (* Harvey P. Dale, Jan 01 2016 *)

PROG

(PARI) list(lim)=my(v=List(), t); forprime(p=2, (lim\8)^(1/7), t=p^7; forprime(q=2, (lim\t)^(1/3), if(p==q, next); listput(v, t*q^3))); vecsort(Vec(v)) \\ Charles R Greathouse IV, Jul 24 2011

CROSSREFS

Sequence in context: A218830 A210626 A278270 * A234893 A251485 A082242

Adjacent sequences:  A179702 A179703 A179704 * A179706 A179707 A179708

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Jul 24 2010

STATUS

approved

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Last modified August 25 09:40 EDT 2019. Contains 326323 sequences. (Running on oeis4.)