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Search: id:A101063
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| A101063 |
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Indices of primes in sequence defined by A(0) = 87, A(n) = 10*A(n-1) - 43 for n > 0. |
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+0
1
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| 1, 19, 32, 61, 67, 85, 194, 523, 529, 656, 1873, 2197
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Numbers n such that (740*10^n + 43)/9 is prime.
Numbers n such that digit 8 followed by n >= 0 occurrences of digit 2 followed by digit 7 is prime.
Numbers corresponding to terms <= 656 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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FORMULA
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a(n) = A103076(n) - 1. - Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 01 2008
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EXAMPLE
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827 is prime, hence 1 is a term.
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PROGRAM
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(PARI) a=87; for(n=0, 1000, if(isprime(a), print1(n, ", ")); a=10*a-43)
(PARI) for(n=0, 1000, if(isprime((740*10^n+43)/9), print1(n, ", ")))
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CROSSREFS
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Cf. A000533, A002275.
Sequence in context: A146659 A160220 A133151 this_sequence A061962 A116168 A152088
Adjacent sequences: A101060 A101061 A101062 this_sequence A101064 A101065 A101066
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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), Nov 30 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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