login
A046391
Odd numbers with exactly 5 distinct prime factors.
7
15015, 19635, 21945, 23205, 25935, 26565, 31395, 33495, 33915, 35805, 36465, 39585, 40755, 41055, 42315, 42735, 45885, 47355, 49335, 49665, 50505, 51051, 51765, 53295, 54285, 55335, 55965, 57057, 57855, 58695, 61215, 61845, 62205
OFFSET
1,1
LINKS
Karl-Heinz Hofmann, Table of n, a(n) for n = 1..10000 (first 1000 terms from T. D. Noe)
EXAMPLE
50505 = 3 * 5 * 7 * 13 * 37.
MAPLE
isA046391 := proc(n)
type(n, 'odd') and (A001221(n) = 5 ) ;
end proc:
for n from 1 do
if isA046391(n) then
print(n);
end if;
end do: # R. J. Mathar, Nov 10 2014
MATHEMATICA
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 *)
PROG
(Python)
from sympy import primefactors, factorint
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
CROSSREFS
Intersection of A051270 and A005408.
Sequence in context: A081635 A165614 A104875 * A339938 A112643 A129485
KEYWORD
nonn
AUTHOR
Patrick De Geest, Jun 15 1998
STATUS
approved