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A366430 Triprimes whose reversal is also a triprime.

%I A366430 #70 Nov 21 2023 10:30:11
%S A366430 8,44,66,99,117,147,165,171,212,222,242,244,246,282,285,286,290,292,
%T A366430 333,338,343,363,366,369,404,406,418,425,434,435,438,442,474,475,494,
%U A366430 498,506,507,508,524,534,539,548,555,561,574,575,582,595,604,605,606,609,628,642,646,663,670,682,705
%N A366430 Triprimes whose reversal is also a triprime.
%H A366430 Robert Israel, <a href="/A366430/b366430.txt">Table of n, a(n) for n = 1..10000</a>
%e A366430 a(5) = 117 is a term because 117 = 3^2 * 13 has 3 prime factors, counted with multiplicity, and so does its reversal 711 = 3^2 * 79.
%p A366430 rev:= proc(n) local L,i;
%p A366430   L:= convert(n,base,10);
%p A366430   add(L[-i]*10^(i-1),i=1..nops(L))
%p A366430 end proc:
%p A366430 select(t -> numtheory:-bigomega(t) = 3 and numtheory:-bigomega(rev(t))=3, [$1..10000]);
%t A366430 Select[Range[710], PrimeOmega[#]==3&&PrimeOmega[FromDigits[Reverse[IntegerDigits[#]]]]==3&] (* _Stefano Spezia_, Nov 07 2023 *)
%o A366430 (Python)
%o A366430 from sympy import factorint
%o A366430 def tp(n): return sum(factorint(n).values()) == 3
%o A366430 def ok(n): return tp(n) and tp(int(str(n)[::-1]))
%o A366430 print([k for k in range(10**3) if ok(k)]) # _Michael S. Branicky_, Nov 21 2023
%Y A366430 Cf. A014612, A085751. Contains A046329. Includes 10*k for k in A367151.
%K A366430 nonn,base
%O A366430 1,1
%A A366430 _Zak Seidov_ and _Robert Israel_, Nov 06 2023