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A083989
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Concatenation of prime k and its 10's complement is a prime.
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4
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3, 7, 17, 23, 29, 31, 41, 43, 53, 67, 71, 83, 109, 127, 139, 151, 173, 179, 197, 211, 229, 263, 271, 281, 307, 359, 463, 547, 557, 569, 587, 593, 673, 677, 683, 691, 701, 719, 727, 757, 769, 823, 839, 881, 883, 887, 907, 937, 983, 997, 1087, 1103, 1171, 1181
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OFFSET
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1,1
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LINKS
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EXAMPLE
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43 belongs to this sequence as 4357 is also a prime.
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MAPLE
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g:= proc(n) local c; c:= 10^(1+ilog10(n))-n; n*10^(1+ilog10(c))+c end proc:
select(t -> isprime(t) and isprime(g(t)), [seq(i, i=3..10000, 2)]); # Robert Israel, Jul 03 2024
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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