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 A221868 Lexicographically earliest sequence of distinct primes in which the concatenation of any number of consecutive terms is composite. 1
 2, 5, 11, 13, 29, 31, 17, 19, 43, 7, 37, 41, 71, 47, 67, 89, 3, 101, 23, 109, 59, 83, 103, 73, 107, 157, 53, 127, 149, 61, 131, 139, 79, 163, 191, 193, 97, 113, 137, 167, 211, 181, 151, 197, 199, 173, 223, 239, 227, 179, 241, 251, 229, 257, 313, 233, 263, 277, 271, 283, 307, 347, 269, 293 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS This sequence is very likely a permutation of the primes. LINKS Hans Havermann, Table of n, a(n) for n = 1..1500 Hans Havermann, Composition EXAMPLE Start with 2. The second term cannot be 3 because the concatenation of 2 and 3 is prime. However, 5 works. The third term cannot be 3 because the concatenation of 5 and 3 is prime. It cannot be 7 because the concatenation of 2 and 5 and 7 is prime. However, 11 works. CROSSREFS Sequence in context: A095078 A062572 A215214 * A220141 A106283 A020629 Adjacent sequences:  A221865 A221866 A221867 * A221869 A221870 A221871 KEYWORD nonn,base AUTHOR Hans Havermann, Apr 10 2013 STATUS approved

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Last modified December 14 21:22 EST 2018. Contains 318138 sequences. (Running on oeis4.)