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Search: id:A075812
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| A075812 |
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Palindromic odd numbers with exactly 2 prime factors (counted with multiplicity). |
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+0
1
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| 9, 33, 55, 77, 111, 121, 141, 161, 303, 323, 393, 505, 515, 535, 545, 565, 707, 717, 737, 767, 939, 949, 959, 979, 989, 1111, 1441, 1661, 1991, 3113, 3223, 3443, 3883, 7117, 7447, 7997, 9119, 9229, 9449, 10001, 10201, 10401, 10801, 10901, 11111
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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9=3^2, 33=3*11 and 55=5*11 are palindromic, odd and are products of exactly 2 prime factors.
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MAPLE
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test := proc(n) local d; d := convert(n, base, 10); return ListTools[Reverse](d)=d and numtheory[bigomega](n)=2; end; a := []; for n from 1 to 14000 by 2 do if test(n) then a := [op(a), n]; end; od; a;
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CROSSREFS
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Cf. A046315.
Sequence in context: A020226 A111351 A065064 this_sequence A146262 A161430 A046895
Adjacent sequences: A075809 A075810 A075811 this_sequence A075813 A075814 A075815
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KEYWORD
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nonn,base
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AUTHOR
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Jani Melik (jani_melik(AT)hotmail.com), Oct 13 2002
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EXTENSIONS
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Edited by Dean Hickerson (dean.hickerson(AT)yahoo.com), Oct 21 2002
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