A113893 Smallest prime obtained as a concatenation of prime(n) and prime(m) with m > n.

23, 37, 523, 719, 1117, 1319, 1723, 1931, 2341, 2953, 3137, 3761, 4153, 4373, 4759, 53101, 59107, 6173, 6779, 71167, 73127, 79103, 8389, 89101, 97103, 101107, 103307, 107137, 109139, 113131, 127139, 131149, 137191, 139199, 149173, 151157, 157163

Offset

1,1

Links

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

Example

a(6) = 1319 as 1317 is composite. prime(6) = 13.

Mathematica

spc[n_]:=Module[{p1=Prime[n], p2}, p2=NextPrime[p1]; While[!PrimeQ[ p1* 10^IntegerLength[ p2]+p2], p2 = NextPrime[p2]]; p1*10^IntegerLength[ p2]+p2]; Array[spc, 40] (* Harvey P. Dale, Apr 05 2018 *)

Crossrefs

Sequence in context: A133980 A090312 A089782 * A146390 A233385 A282712

Adjacent sequences: A113890 A113891 A113892 * A113894 A113895 A113896

Keyword

base,nonn

Author

Amarnath Murthy, Nov 18 2005

Extensions

More terms from Stefan Steinerberger and Jim Nastos, Nov 18 2005

Status

approved