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A221309
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Numbers m such that no subset of {m-1, m, m+1} sums up to a prime number.
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3
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25, 77, 85, 92, 93, 94, 118, 122, 123, 124, 133, 143, 144, 145, 160, 161, 170, 171, 185, 188, 202, 203, 206, 207, 208, 213, 214, 218, 235, 236, 237, 247, 248, 253, 259, 265, 266, 267, 275, 287, 290, 291, 295, 298, 302, 305, 319, 325, 328, 333, 334, 335, 340
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listen;
history;
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internal format)
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OFFSET
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1,1
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COMMENTS
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A117499(a(n)) = 0.
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LINKS
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Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
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EXAMPLE
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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.
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PROG
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(Haskell)
a221309 n = a221309_list !! (n-1)
a221309_list = map (+ 1) $ elemIndices 0 a117499_list
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CROSSREFS
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Subsequence of A079364.
Sequence in context: A042228 A042230 A189642 * A192504 A033658 A080699
Adjacent sequences: A221306 A221307 A221308 * A221310 A221311 A221312
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KEYWORD
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nonn
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AUTHOR
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Reinhard Zumkeller, Jan 10 2013
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STATUS
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approved
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