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%I #10 Dec 30 2023 23:15:22
%S 91,14,34,74,35,95,38,301,901,721,731,361,371,391,791,922,142,362,382,
%T 703,713,133,943,763,973,793,914,134,334,934,974,194,305,905,145,745,
%U 755,365,965,785,395,995,106,706,146,346,746,166,386,917,377,118,358,758,958,778,119,749,779,799,3101
%N Semiprimes whose reversal is a prime, ordered by the prime.
%H Robert Israel, <a href="/A368238/b368238.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = A004086(A085778(n)).
%e a(4) = 74 because A115670(4) = 47 is the 4th prime whose reversal is a semiprime, and 74 is that reversal.
%p rev:= proc(n) local L,i;
%p L:= convert(n,base,10);
%p add(L[-i]*10^(i-1),i=1..nops(L))
%p end proc:
%p map(rev, select(p -> isprime(p) and numtheory:-bigomega(rev(p)) = 2, [seq(i,i=3..1000,2)]);
%t s = {}; Do[If[2 == PrimeOmega[sm = FromDigits[Reverse[IntegerDigits[Prime[k]]]]], AppendTo[s, sm]], {k, 200}]; s
%Y Cf. A001358, A004086, A085778, A115670.
%K nonn,base
%O 1,1
%A _Zak Seidov_ and _Robert Israel_, Dec 18 2023
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