A221868 Lexicographically earliest sequence of distinct primes in which the concatenation of any number of consecutive terms is composite.

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

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: A335874 A062572 A215214 * A220141 A106283 A020629

Adjacent sequences: A221865 A221866 A221867 * A221869 A221870 A221871

Keyword

nonn,base

Author

Hans Havermann, Apr 10 2013

Status

approved