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A109031 Numbers that have exactly eleven prime factors counted with multiplicity (A069272) whose digit reversal is different and also has 11 prime factors (with multiplicity).

%I A109031 #21 Feb 16 2025 08:32:58
%S A109031 295245,426816,542592,618624,2112480,2116224,2150064,2154816,2196000,
%T A109031 2302560,2327616,2342277,2388672,2555280,2576896,2599200,2768832,
%U A109031 2952288,2952576,4017216,4074240,4074840,4076160,4076568,4078848
%N A109031 Numbers that have exactly eleven prime factors counted with multiplicity (A069272) whose digit reversal is different and also has 11 prime factors (with multiplicity).
%C A109031 This sequence is the k = 11 instance of the series which begins with k = 1 (emirps), k = 2, k = 3 (A109023), k = 4 (A109024), k = 5 (A109025), k = 6 (A109026), k = 7 (A109027), k = 8 (A109028), k = 9 (A109029), k = 10 (A109030).
%H A109031 David A. Corneth, <a href="/A109031/b109031.txt">Table of n, a(n) for n = 1..10000</a>
%H A109031 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/AlmostPrime.html">Almost Prime</a>.
%H A109031 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Emirp.html">Emirp</a>.
%H A109031 Eric Weisstein and Jonathan Vos Post, <a href="https://mathworld.wolfram.com/Emirpimes.html">Emirpimes</a>.
%e A109031 a(1) = 295245 is in this sequence because 295245 = 3^10 * 5 has exactly 11 prime factors counted with multiplicity and reverse(295245) = 542592 = 2^7 * 3^3 * 157 also has 11 prime factors counted with multiplicity.
%o A109031 (PARI) is(n) = {
%o A109031 	my(r = fromdigits(Vecrev(digits(n))));
%o A109031 	n!=r && bigomega(n) == 11 && bigomega(r) == 11
%o A109031 } \\ _David A. Corneth_, Mar 07 2024
%Y A109031 Cf. A069272, A006567, A097393, A109018, A109023, A109024, A109025, A109026, A109027, A109028, A109029, A109030.
%K A109031 nonn,base
%O A109031 1,1
%A A109031 _Jonathan Vos Post_, Jun 16 2005
%E A109031 a(5)-a(25) from _Donovan Johnson_, Apr 09 2010