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Search: id:A102024
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| A102024 |
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Indices of primes in sequence defined by A(0) = 17, A(n) = 10*A(n-1) - 3 for n > 0. |
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+0
1
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| 0, 1, 2, 4, 8, 10, 13, 31, 53, 54, 59, 152, 199, 460, 568, 839, 846, 1295, 1355, 2006, 2626, 2846, 3109, 6875, 9160
(list; graph; listen)
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OFFSET
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1,3
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COMMENT
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Numbers n such that (150*10^n + 3)/9 is prime.
Numbers n such that digit 1 followed by n >= 0 occurrences of digit 6 followed by digit 7 is prime.
Numbers corresponding to terms <= 846 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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167 is prime, hence 1 is a term.
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PROGRAM
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(PARI) a=17; for(n=0, 1500, if(isprime(a), print1(n, ", ")); a=10*a-3)
(PARI) for(n=0, 1500, if(isprime((150*10^n+3)/9), print1(n, ", ")))
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CROSSREFS
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Cf. A000533, A002275.
a(n) = A102940(n) - 1.
Sequence in context: A014190 A141400 A030232 this_sequence A104197 A047235 A087505
Adjacent sequences: A102021 A102022 A102023 this_sequence A102025 A102026 A102027
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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 28 2004
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EXTENSIONS
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More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008
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