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A384636 Triprimes that are the concatenation of three consecutive primes in reverse order.

%I A384636 #13 Jun 09 2025 11:13:00
%S A384636 1175,231917,434137,534743,595347,10310197,107103101,137131127,
%T A384636 149139137,163157151,167163157,179173167,223211199,239233229,
%U A384636 251241239,269263257,281277271,293283281,311307293,349347337,383379373,401397389,419409401,421419409,449443439,457449443,487479467,491487479
%N A384636 Triprimes that are the concatenation of three consecutive primes in reverse order.
%H A384636 Robert Israel, <a href="/A384636/b384636.txt">Table of n, a(n) for n = 1..10000</a>
%e A384636 a(3) = 434137 is a term because it is the concatenation in reverse order of the three consecutive primes 37, 41 and 43, and 434137 = 11 * 61 * 647 is the product of three primes.
%p A384636 cat3:= proc(a,b,c)
%p A384636   (a*10^(1+ilog10(b))+b)*10^(1+ilog10(c))+c
%p A384636 end proc:
%p A384636 select(t -> numtheory:-bigomega(t) = 3, [seq(cat3(ithprime(i+2),ithprime(i+1),ithprime(i)),i=1..100)]);
%t A384636 p3[p_]:=FromDigits[Join[IntegerDigits[Prime[p+2]],IntegerDigits[Prime[p+1]],IntegerDigits[Prime[p]]]];Select[Array[p3,100],PrimeOmega[#]==3&] (* _James C. McMahon_, Jun 09 2025 *)
%Y A384636 Cf. A014612, A383114, A384638.
%K A384636 nonn,base
%O A384636 1,1
%A A384636 _Will Gosnell_ and _Robert Israel_, Jun 05 2025