A156121 First prime of a pair, formed by concatenating n, n+1, the second prime (not shown) formed by concatenating n+2, n+3.

67, 7879, 9091, 186187, 276277, 426427, 438439, 450451, 600601, 606607, 798799, 816817, 858859, 936937, 960961, 11401141, 13981399, 15361537, 17461747, 17881789, 18961897, 21002101, 21902191, 22082209, 27362737, 28802881

Offset: 1

Author

Ki Punches, Feb 16 2009

Keywords

• nonn
• base

Examples

			For n=6 the primes generated are 67 and 89 so 67 is in the sequence.
		

Links

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

Programs

Mathematica

fd[lst_]:=FromDigits[Flatten[IntegerDigits/@lst]]; ppcQ[n_]:=And@@ PrimeQ[ {fd[{n,n+1}],fd[{n+2,n+3}]}]; fd[{#,#+1}]&/@Select[Range[10000],ppcQ] (* Harvey P. Dale, Aug 07 2013 *)

Extensions

Edited and extended by Ray Chandler, Feb 20 2009