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 A221309 Numbers m such that no subset of {m-1, m, m+1} sums up to a prime number. 3
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS A117499(a(n)) = 0. LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 EXAMPLE 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. PROG (Haskell) a221309 n = a221309_list !! (n-1) a221309_list = map (+ 1) \$ elemIndices 0 a117499_list CROSSREFS Subsequence of A079364. Sequence in context: A042228 A042230 A189642 * A192504 A033658 A080699 Adjacent sequences: A221306 A221307 A221308 * A221310 A221311 A221312 KEYWORD nonn AUTHOR Reinhard Zumkeller, Jan 10 2013 STATUS approved

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Last modified March 21 22:04 EDT 2023. Contains 361411 sequences. (Running on oeis4.)