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List of pairs of consecutive nonprime odd numbers {m-1,m+1}.
1

%I #9 Apr 24 2020 18:54:29

%S 25,27,33,35,49,51,55,57,63,65,75,77,85,87,91,93,93,95,115,117,117,

%T 119,119,121,121,123,123,125,133,135,141,143,143,145,145,147,153,155,

%U 159,161,169,171,175,177,183,185,185,187,187,189

%N List of pairs of consecutive nonprime odd numbers {m-1,m+1}.

%t Flatten[Table[If[OddQ[n - 1] && PrimeQ[n - 1] == False && PrimeQ[n + 1] == False, {{n - 1}, {n + 1}}, {}], {n, 2, 200}]]

%t Select[Partition[Range[1,201,2],2,1],NoneTrue[#,PrimeQ]&]//Flatten (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Apr 09 2019 *)

%Y Cf. A061673, A093708.

%K nonn

%O 1,1

%A _Roger L. Bagula_, May 20 2007