A253245 Primes that are the concatenation of prime(n) and prime(n+2).

37, 1117, 1319, 1723, 4759, 89101, 97103, 101107, 113131, 151163, 181193, 223229, 227233, 239251, 251263, 293311, 313331, 337349, 389401, 421433, 461467, 491503, 587599, 631643, 647659, 683701, 691709, 701719, 739751, 761773, 809821

Offset: 1

Author

Altug Alkan, Aug 22 2015

Keywords

• nonn
• easy
• base

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A000040, A030461.

Programs

Mathematica

Module[{nn=300,pr},pr={#[[1]],#[[3]]}&/@Partition[Prime[Range[nn]],3,1];Select[Table[FromDigits[Flatten[IntegerDigits/@pr[[n]]]],{n, Length[ pr]}],PrimeQ]] (* Harvey P. Dale, Nov 29 2015 *)

PARI

for(n=1, 1e3, if(isprime(k=eval(Str(prime(n), prime(n+2)))), print1(k", ")))