A086102 Concatenation of last two digits of p(n) and first two digits of p(n+1) is prime; values of such n in the sequence.

11, 23, 29, 31, 44, 45, 51, 58, 61, 66, 73, 80, 82, 84, 111, 112, 124, 127, 130, 136, 138, 167, 185, 186, 188, 192, 194, 212, 213, 215, 216, 217, 218, 275, 276, 292, 293, 294, 295, 296, 297, 299, 300, 301, 302, 319, 321, 326, 344, 345, 346, 348, 352, 353, 355

Offset

1,1

Links

Table of n, a(n) for n=1..55.

Example

a(7)=51 because prime(51)=233, prime(52)=239 and 3323 is prime.

Mathematica

cpdQ[{a_, b_}]:=PrimeQ[FromDigits[Join[Take[IntegerDigits[a], -2], Take[ IntegerDigits[b], 2]]]]; PrimePi/@Transpose[Select[ Partition[ Prime[ Range[5, 500]], 2, 1], cpdQ]][[1]]  (* Harvey P. Dale, Mar 30 2011 *)

Crossrefs

Sequence in context: A257318 A090423 A232085 * A058340 A138537 A271983

Adjacent sequences: A086099 A086100 A086101 * A086103 A086104 A086105

Keyword

easy,nonn,base

Author

Zak Seidov, Jul 09 2003

Extensions

Edited by Charles R Greathouse IV, Apr 27 2010

Status

approved