%I #24 Aug 20 2021 04:24:22
%S 51,62,85,93,94,221,302,321,341,381,413,442,492,493,502,511,513,514,
%T 522,524,533,534,551,553,561,562,574,581,582,604,605,621,622,623,642,
%U 663,682,685,705,711,723,734,741,766,771,781,794,805,814,817
%N If composite k and its reverse are different and have same number of prime factors, then the larger of them is a term of the sequence.
%e a(n)=341 -> reverse(a(n)) = 143 gives the pair (143,341) of which only the larger value 341 is retained.
%t rev[n_]:=FromDigits[Reverse[IntegerDigits[n]]]; Select[Range[825],!PrimeQ[#]&&PrimeOmega[#]==PrimeOmega[x=rev[#]]&&#>x&] (* _Jayanta Basu_, May 31 2013 *)
%o (PARI) isok(m) = my(k=fromdigits(Vecrev(digits(m)))); (m%10) && !isprime(m) && (m>k) && (bigomega(k) == bigomega(m)); \\ _Michel Marcus_, Aug 18 2021
%Y Cf. A004086, A050699, A050700.
%K nonn,base
%O 1,1
%A _Patrick De Geest_, Aug 15 1999
%E Revised by Editors of OEIS, Oct 19 2019
%E Incorrect 394 and 523 removed and name clarified by _Sean A. Irvine_, Aug 17 2021