%I #7 Jul 13 2013 12:04:36

%S 25,77,85,92,93,94,118,122,123,124,133,143,144,145,160,161,170,171,

%T 185,188,202,203,206,207,208,213,214,218,235,236,237,247,248,253,259,

%U 265,266,267,275,287,290,291,295,298,302,305,319,325,328,333,334,335,340

%N Numbers m such that no subset of {m-1, m, m+1} sums up to a prime number.

%C A117499(a(n)) = 0.

%H Reinhard Zumkeller, <a href="/A221309/b221309.txt">Table of n, a(n) for n = 1..10000</a>

%e a(1) = 25: there are 7 nonempty subsets of {25-1, 25, 25+1}: {24}, {25}, {26}, {24,25}, {24,26}, {25,26} and {24,25,26} with sums and factorizations: 24=3*2^3, 25=5^2, 26=13*2, 49=7^2, 50=5^2*2, 51=17*3 and 75=5^2*3.

%o (Haskell)

%o a221309 n = a221309_list !! (n-1)

%o a221309_list = map (+ 1) $ elemIndices 0 a117499_list

%Y Subsequence of A079364.

%K nonn

%O 1,1

%A _Reinhard Zumkeller_, Jan 10 2013