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Search: id:A082549
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| A082549 |
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Numbers n such that concatenation of first n primes, separated by zeros, is prime. |
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+0
4
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OFFSET
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1,2
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COMMENT
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w_n= (p_1)0(p_2)0(p_3)...0(p_n) w_1=2 is prime(a_1=1), w_2, ..., w_8 are not prime, and w_9 is prime (a_2=9),... a_n is the n-th term of w_n which is prime.
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EXAMPLE
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a(2)=9 because 2030507011013017019023, which is the concatenation of first 9 primes separated by zeros is prime.
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CROSSREFS
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Adjacent sequences: A082546 A082547 A082548 this_sequence A082550 A082551 A082552
Sequence in context: A079290 A109888 A014003 this_sequence A013569 A129401 A046353
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KEYWORD
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base,hard,more,nonn
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AUTHOR
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Farideh Firoozbakht (Farideh_Firoozbakht(AT)math.com), May 03 2003
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