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A034591
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Numbers whose concatenation with the next prime yields a prime.
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5
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0, 2, 6, 8, 9, 12, 27, 31, 36, 42, 44, 45, 51, 56, 63, 68, 69, 78, 83, 86, 93, 94, 96, 98, 102, 104, 105, 108, 115, 117, 118, 123, 126, 132, 138, 150, 151, 154, 156, 157, 160, 167, 176, 180, 183, 186, 192, 194, 195, 199, 201, 205, 213, 217, 219, 225, 230, 233
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OFFSET
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1,2
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LINKS
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EXAMPLE
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8 is a term because nextprime(8) = 11 and 811 is prime.
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MATHEMATICA
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Select[Range[0, 250], PrimeQ@FromDigits@Flatten[IntegerDigits/@{#, NextPrime@#}]&] (* Giorgos Kalogeropoulos, Jul 30 2021 *)
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PROG
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(PARI) isok(m) = isprime(eval(Str(m, nextprime(m+1)))); \\ Michel Marcus, Oct 03 2014 and Jul 30 2021
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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