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Four-digit primes such that simultaneously swapping the first two digits and swapping the last two digits produces another prime.
1

%I #12 Mar 11 2020 05:59:51

%S 1013,1019,1031,1039,1093,1097,1117,1171,1213,1231,1297,1319,1373,

%T 1433,1493,1531,1579,1597,1613,1637,1699,1777,1811,1871,1933,1973,

%U 1999,2011,2017,2039,2113,2131,2179,2237,2239,2273,2293,2371,2399,2411,2417,2437,2579

%N Four-digit primes such that simultaneously swapping the first two digits and swapping the last two digits produces another prime.

%C The second digit of the number is allowed to be zero, the resulting zero digit is ignored.

%H Harvey P. Dale, <a href="/A266369/b266369.txt">Table of n, a(n) for n = 1..201</a> (The complete list of terms)

%e 1013 is a member because (0)131 = 131 is a prime.

%t swprQ[n_]:=Module[{idn=IntegerDigits[n]},PrimeQ[FromDigits[ {idn[[2]], idn[[1]], idn[[4]], idn[[3]]}]]]; Select[Prime[Range[ PrimePi[ 1000]+ 1, PrimePi[ 10000]]],swprQ]

%K nonn,fini,full,base

%O 1,1

%A _Harvey P. Dale_, Dec 28 2015