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Search: id:A101151
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| A101151 |
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Indices of primes in sequence defined by A(0) = 73, A(n) = 10*A(n-1) + 53 for n > 0. |
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1
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OFFSET
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1,2
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COMMENT
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Numbers n such that (710*10^n - 53)/9 is prime.
Numbers n such that digit 7 followed by n >= 0 occurrences of digit 8 followed by digit 3 is prime.
Numbers corresponding to terms <= 287 are certified primes.
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REFERENCES
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Klaus Brockhaus and Walter Oberschelp, Zahlenfolgen mit homogenem Ziffernkern, MNU 59/8 (2006), pp. 462-467.
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LINKS
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Makoto Kamada, Factorizations of near-repdigit numbers.
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EXAMPLE
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7888883 is prime, hence 5 is a term.
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PROGRAM
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(PARI) a=73; for(n=0, 1500, if(isprime(a), print1(n, ", ")); a=10*a+53)
(PARI) for(n=0, 1500, if(isprime((710*10^n-53)/9), print1(n, ", ")))
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CROSSREFS
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Cf. A000533, A002275.
a(n) = A103066(n) - 1.
Sequence in context: A073422 A006525 A042161 this_sequence A138788 A030244 A004150
Adjacent sequences: A101148 A101149 A101150 this_sequence A101152 A101153 A101154
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KEYWORD
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nonn,hard,more
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AUTHOR
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Klaus Brockhaus (klaus-brockhaus(AT)t-online.de) and Walter Oberschelp (oberschelp(AT)informatik.rwth-aachen.de), Dec 03 2004
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EXTENSIONS
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More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 01 2008
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