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A046391 Odd numbers with exactly 5 distinct prime factors. 7

%I #23 Mar 01 2023 11:04:08

%S 15015,19635,21945,23205,25935,26565,31395,33495,33915,35805,36465,

%T 39585,40755,41055,42315,42735,45885,47355,49335,49665,50505,51051,

%U 51765,53295,54285,55335,55965,57057,57855,58695,61215,61845,62205

%N Odd numbers with exactly 5 distinct prime factors.

%H Karl-Heinz Hofmann, <a href="/A046391/b046391.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from T. D. Noe)

%e 50505 = 3 * 5 * 7 * 13 * 37.

%p isA046391 := proc(n)

%p type(n,'odd') and (A001221(n) = 5 ) ;

%p end proc:

%p for n from 1 do

%p if isA046391(n) then

%p print(n);

%p end if;

%p end do: # _R. J. Mathar_, Nov 10 2014

%t f[n_]:=Last/@FactorInteger[n]=={1,1,1,1,1}&&FactorInteger[n][[1,1]]>2; lst={};Do[If[f[n],AppendTo[lst,n]],{n,9!}];lst (* _Vladimir Joseph Stephan Orlovsky_, Nov 23 2009 *)

%o (Python)

%o from sympy import primefactors, factorint

%o print([n for n in range(1, 100000, 2) if len(primefactors(n)) == 5 and max(list(factorint(n).values())) < 2]) # _Karl-Heinz Hofmann_, Mar 01 2023

%Y Cf. A046318, A046407.

%Y Intersection of A051270 and A005408.

%K nonn

%O 1,1

%A _Patrick De Geest_, Jun 15 1998

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Last modified August 8 22:42 EDT 2024. Contains 375024 sequences. (Running on oeis4.)