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A088104
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Smallest n-digit prime beginning with prime(n), or 0 if no such prime exists.
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7
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2, 31, 503, 7001, 11003, 130003, 1700021, 19000013, 230000003, 2900000017, 31000000027, 370000000003, 4100000000003, 43000000000063, 470000000000023, 5300000000000129, 59000000000000011, 610000000000000031, 6700000000000000021, 71000000000000000047, 730000000000000000001
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OFFSET
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1,1
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COMMENTS
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Conjecture: No term is zero. Subsidiary sequences: (1) A088754 = number of n-digit primes beginning with prime(n). (2) A088755 = number of n-digit primes beginning with n.
If Legendre's conjecture is true, then no term is zero. - Chai Wah Wu, Jun 18 2019
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LINKS
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EXAMPLE
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a(6) = 130003 begins with prime(6) = 13 and has 6 digits.
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MATHEMATICA
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Prepend[NextPrime[FromDigits[PadRight[IntegerDigits[#], PrimePi[#]]]]&/@Prime[Range[2, 25]], 2] (* Harvey P. Dale, Jan 09 2011 *)
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PROG
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(PARI) a(n) = my(p=prime(n), d=digits(p)); c=nextprime(p*10^(n-#d)); cd=digits(c); if(vector(#d, i, cd[i]) == d, return(c), return(0)) \\ David A. Corneth, Apr 13 2019
(Python)
from sympy import prime, nextprime
p = prime(n)
return nextprime(p*10**(n-len(str(p)))-1) # Chai Wah Wu, Jun 18 2019
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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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