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A070955
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Numbers n such that n concatenated with n-1 0's and its reversal is prime.
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0
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OFFSET
| 1,2
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COMMENTS
| a(2) and a(3) certified prime with Primo. a(4) is a probable prime.
a(7) > 10^4.
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EXAMPLE
| a(2)=122 because 12200...(121 zeros)...000221 is prime.
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CROSSREFS
| Sequence in context: A099154 A158131 A004925 * A195856 A116216 A203805
Adjacent sequences: A070952 A070953 A070954 * A070956 A070957 A070958
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KEYWORD
| base,more,nonn
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AUTHOR
| Jason Earls (zevi_35711(AT)yahoo.com), May 25 2002
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EXTENSIONS
| a(5), a(6) from Max Alekseyev (maxale(AT)gmail.com), May 21 2011
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