A154531 Primes that are a concatenation of consecutive primes in two ways.

199211, 211199, 233239, 239233, 257263, 263257, 353359, 359353, 523541, 541523, 653659, 659653, 971977, 977971, 19731979, 19791973, 23332339, 23392333, 32593271, 32713259, 36373643, 36433637, 37613767, 37673761, 42834289, 42894283, 49934999, 49994993

Offset

1,1

Links

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

Example

233 and 239 consecutive primes, 233239 and 239233 are both primes.

Mathematica

ccp2[{a_, b_}]:=Module[{c=a*10^IntegerLength[b]+b, d=b*10^IntegerLength[a]+ a}, If[ AllTrue[ {c, d}, PrimeQ], {c, d}, {}]]; ccp2/@Partition[Prime[ Range[ 1000]], 2, 1]//Flatten (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Feb 20 2017 *)

Crossrefs

Cf. A133986, A154530.

Sequence in context: A205638 A031687 A234034 * A043592 A126558 A339752

Adjacent sequences: A154528 A154529 A154530 * A154532 A154533 A154534

Keyword

nonn,base

Author

Pierre CAMI, Jan 11 2009

Extensions

Corrected by Harvey P. Dale, Feb 20 2017

Status

approved