A084669 Primes which are a concatenation of prime(n) and n.

53, 239, 6719, 7321, 15737, 30763, 38977, 41981, 44987, 587107, 661121, 751133, 1051177, 1229201, 1297211, 1303213, 1327217, 1823281, 1913293, 1999303, 2131321, 2179327, 2207329, 2239333, 2371351, 2689391, 2699393, 3067439

Offset: 1

Author

Zak Seidov, Jun 29 2003

Keywords

• nonn
• base

Examples

			a(2)=239 because prime[9]=23 and concatenation of 23 and 9 is 239 which is prime.
		

Crossrefs

Cf. A084667.

Subsequence of primes of A075110.

Programs

Magma

[p: n in [1..500] | IsPrime(p) where p is Seqint(Intseq(n) cat Intseq(NthPrime(n)))]; // Bruno Berselli, Sep 15 2015

Mathematica

Select[Table[FromDigits[Flatten[{IntegerDigits[Prime[n]], IntegerDigits[n]}]], {n, 1, 500}], PrimeQ]