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A160955
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a(n+1) is the largest prime formed by appending a single digit to a(n); a(1)=18.
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2
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OFFSET
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1,1
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COMMENTS
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There is no prime a(7) since 18119930 to 18119939 are all composite.
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LINKS
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EXAMPLE
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a(1)=18,
a(2)=181,
a(3)=1811,
a(4)=18119,
a(5)=181199,
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MAPLE
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A160955 :=proc(n) option remember ; local d; if n =1 then 18; else for d from 1 to 9 by 2 do if isprime(10*prochame n+d) then RETURN(10*procnam n+d 0 ; fi; end:
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CROSSREFS
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KEYWORD
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nonn,base,easy,fini,full
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AUTHOR
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EXTENSIONS
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Redundant part of the definition removed by R. J. Mathar, May 21 2010
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STATUS
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approved
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