A103195 Concatenations of pairs of primes that differ by four.

37, 711, 1317, 1923, 3741, 4347, 6771, 7983, 97101, 103107, 109113, 127131, 163167, 193197, 223227, 229233, 277281, 307311, 313317, 349353, 379383, 397401, 439443, 457461, 463467, 487491, 499503, 613617, 643647, 673677, 739743, 757761, 769773

Offset: 1

Author

Parthasarathy Nambi, Mar 18 2005

Keywords

• nonn
• base

Examples

			The primes 3 and 7 differ by four, so the first term is 37.
		

Links

• Chris Caldwell, The First 1,000 Primes.
• Eric Weisstein's World of Mathematics, Cousin Primes.
• M. Wolf, On Twin and Cousin Primes.

Programs

Mathematica

s = Select[ Prime[ Range[ 140]], PrimeQ[ # + 4] &]; FromDigits /@ Join @@@ IntegerDigits /@ Transpose[{s, s + 4}] (* Robert G. Wilson v, Mar 19 2005 *)
Join[{37},FromDigits[Flatten[IntegerDigits/@#]]&/@Select[Partition[ Prime[ Range[ 200]],2,1],#[[2]]-#[[1]]==4&]] (* Harvey P. Dale, Sep 26 2016 *)

Formula

a(n) = A023200(n) concatenated with A023200(n)+4. - Jonathan Vos Post, Mar 19 2005

Extensions

More terms from Robert G. Wilson v, Mar 19 2005