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%I #4 Jan 14 2014 10:08:37
%S 2,3,5,7,17,19,23,41,79,89,101,103,113,137,139,149,199,211,233,239,
%T 257,271,281,311,353,367,401,521,761,809,929,953,1087,1217,1303,1327,
%U 1361,1433,1553,1721,1759,1879,1951,1999,2039,2069,2081,2179,2417,2441,2777
%N Prime p of the form a^b - c^d = p, where a, b, c, d are also primes.
%e 3^3 - 5^2 = 2; 2^7 - 5^3 = 3; 3^2 - 2^2 = 5; 2^5 - 5^2 = 7;
%t Take[Select[Union[Abs[#[[1]]^#[[2]]-#[[3]]^#[[4]]]&/@Tuples[Prime[ Range[ 30]],4]],PrimeQ],60] (* _Harvey P. Dale_, Jan 14 2014 *)
%K nonn
%O 1,1
%A _Oleg Zyakun_, Aug 12 2009
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