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

1,1

Links

Table of n, a(n) for n=1..33.

Chris Caldwell, The First 1,000 Primes.

Eric Weisstein's World of Mathematics, Cousin Primes.

M. Wolf, On Twin and Cousin Primes.

Formula

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

Example

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

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 *)

Crossrefs

Sequence in context: A162165 A162389 A010989 * A282927 A220684 A225971

Adjacent sequences: A103192 A103193 A103194 * A103196 A103197 A103198

Keyword

nonn,base

Author

Parthasarathy Nambi, Mar 18 2005

Extensions

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

Status

approved