A238647 Primes which are not the concatenation of two primes.

2, 3, 5, 7, 11, 13, 17, 19, 29, 31, 41, 43, 47, 59, 61, 67, 71, 79, 83, 89, 97, 101, 103, 107, 109, 127, 131, 139, 149, 151, 157, 163, 167, 179, 181, 191, 199, 227, 239, 251, 257, 263, 269, 277, 281, 307, 349, 401, 409, 419, 421, 431, 439, 443, 449, 457, 461

Offset

1,1

Comments

223 is the first term in A141409 which is not in this sequence.

In this sequence, a prime preceded by one or more zeros is not considered to be a prime.

Links

Table of n, a(n) for n=1..57.

Example

59 is in the sequence because 5 is prime but 9 is not prime.
223 is not in the sequence because both 2 and 23 are primes.

Crossrefs

Cf. A141409, A105184 (complement), A238056, A238057, A238499.

Sequence in context: A133956 A176164 A141409 * A348358 A171821 A004051

Adjacent sequences: A238644 A238645 A238646 * A238648 A238649 A238650

Keyword

nonn,base

Author

Colin Barker, Mar 02 2014

Status

approved