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A154531 Primes that are a concatenation of consecutive primes in two ways. 2
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified June 18 04:41 EDT 2021. Contains 345098 sequences. (Running on oeis4.)