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%I #11 Aug 28 2022 10:37:38
%S 1518,2046,2226,2262,2418,2478,2618,2622,2814,2838,2886,3135,3927,
%T 4170,4182,4386,4389,4746,4785,4935,5313,5394,5406,5478,5565,5655,
%U 5838,5874,6018,6045,6222,6402,6438,6474,6486,6690,6699,6834,6846,6882,7293,7458,8106,8142
%N Tetraprimes (products of four distinct primes) whose reversals are different tetraprimes.
%C Palindromic tetraprimes are A046394.
%C The corresponding sequence for three distinct primes is A270175.
%e 1518 = 2*3*11*23 is a tetraprime. Its reversal 8151 = 3*11*13*19 is another tetraprime. Thus, 1518 is in this sequence.
%t Select[Range[10000],Transpose[ FactorInteger[FromDigits[Reverse[IntegerDigits[#]]]]][[2]] == {1, 1, 1, 1} && IntegerDigits[#] != Reverse[IntegerDigits[#]] && Transpose[FactorInteger[#]][[2]] == {1, 1, 1, 1} &]
%o (Python)
%o from sympy import factorint
%o def tetra(n): return list(factorint(n).values()) == [1, 1, 1, 1]
%o def ok(n):
%o if not tetra(n): return False
%o revn = int(str(n)[::-1])
%o return n != revn and tetra(revn)
%o print([k for k in range(9000) if ok(k)]) # _Michael S. Branicky_, Aug 27 2022
%Y Cf. A046394, A270175.
%K nonn,base
%O 1,1
%A _Tanya Khovanova_, Aug 26 2022