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A006567 Emirps (primes whose reversal is a different prime).
(Formerly M4887)
+0
49
13, 17, 31, 37, 71, 73, 79, 97, 107, 113, 149, 157, 167, 179, 199, 311, 337, 347, 359, 389, 701, 709, 733, 739, 743, 751, 761, 769, 907, 937, 941, 953, 967, 971, 983, 991, 1009, 1021, 1031, 1033, 1061, 1069, 1091, 1097, 1103, 1109, 1151, 1153, 1181, 1193 (list; graph; listen)
OFFSET

1,1

REFERENCES

M. Gardner, The Magic Numbers of Dr Matrix. Prometheus, Buffalo, NY, 1985, p. 230.

LINKS

T. D. Noe, Table of n, a(n) for n=1..10000

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

C. K. Caldwell, The Prime Glossary, emirp

MATHEMATICA

f[n_] := ToExpression[StringReverse[ToString[n]]]; Select[ Range[ 1200 ], PrimeQ[ f[ # ] ] && PrimeQ[ # ] && f[ # ] != # & ] - from Santi Spadaro (spados(AT)katamail.com), Oct 14 2001

ndig[ a_, b_ ] := 10a + b tonum[ dig_ ] := Fold[ ndig, 0, dig ] f[ n_ ] := tonum[ Reverse[ IntegerDigits[ n ] ] ] Select[ Range[ 1200 ], PrimeQ[ f[ # ] ] && PrimeQ[ # ] && f[ # ] =!= # & ] - from Santi Spadaro (spados(AT)katamail.com), Oct 14 2001

PROGRAM

(MAGMA) [ n : n in [1..1194] | n ne rev and IsPrime(n) and IsPrime(rev) where rev is Seqint(Reverse(Intseq(n))) ]; - from Sergei Haller (sergei(AT)sergei-haller.de), Dec 21 2006

CROSSREFS

Cf. A003684, A007628, A046732, A048051, A048052, A048053, A048054, A048895.

Adjacent sequences: A006564 A006565 A006566 this_sequence A006568 A006569 A006570

Sequence in context: A048520 A033210 A107159 this_sequence A108388 A083983 A129338

KEYWORD

nonn,nice,easy,base

AUTHOR

njas

EXTENSIONS

More terms from James A. Sellers (sellersj(AT)math.psu.edu), Jan 22 2000

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Last modified May 14 01:44 EDT 2008. Contains 139663 sequences.


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