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A167518
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Least reversible prime (A007500) which is a concatenation of n consecutive primes.
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1
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2, 151157, 353359367, 139149151157, 101103107109113, 704517045770459704817048770489, 97101103107109113127, 1519315199152171522715233152411525915263, 382138233833384738513853386338773881, 9319932393379341934393499371937793919397
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OFFSET
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1,1
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COMMENTS
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Here the weaker definition of A007500 is used, but all terms > 2 known so far are also Emirps in the sense of A006567 (i.e. different from their reversal), so it is sufficient to change the first term to 13 in order to have a sequence of "true" emirps.
Is it possible to prove that all terms > 2 are in A006567?
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LINKS
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Table of n, a(n) for n=1..10.
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PROG
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(PARI) for(k=1, 19, for(i=0, 1e9, isprime( eval( p=concat( vector( k, j, Str( prime( i+j )))))) & isprime(eval(concat(vecextract(Vec(p), "-1..1")))) & break); print1(p, ", "))
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CROSSREFS
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Cf. A030997, A167517.
Sequence in context: A170995 A003840 A122540 * A178168 A006935 A070833
Adjacent sequences: A167515 A167516 A167517 * A167519 A167520 A167521
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KEYWORD
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nonn,base
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AUTHOR
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M. F. Hasler, Nov 10 2009
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EXTENSIONS
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Edited by Charles R Greathouse IV, Apr 28 2010
a(9)-a(10) from Donovan Johnson, Sep 25 2011
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STATUS
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approved
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