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Search: id:A101005
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| A101005 |
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Indices of primes in sequence defined by A(0) = 97, A(n) = 10*A(n-1) - 33 for n > 0. |
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+0
1
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| 0, 1, 2, 3, 14, 26, 70, 85, 104, 241, 249, 447, 538, 783, 813, 1024, 1171, 1352, 3008, 3174, 3681, 6992, 7611, 7779, 9632
(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 (840*10^n + 33)/9 is prime.
Numbers n such that digit 9 followed by n >= 0 occurrences of digit 3 followed by digit 7 is prime.
Numbers corresponding to terms <= 1024 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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9337 is prime, hence 2 is a term.
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PROGRAM
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(PARI) a=97; for(n=0, 1500, if(isprime(a), print1(n, ", ")); a=10*a-33)
(PARI) for(n=0, 1500, if(isprime((840*10^n+33)/9), print1(n, ", ")))
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CROSSREFS
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Cf. A000533, A002275.
a(n) = A103096(n) - 1.
Sequence in context: A025092 A112636 A124663 this_sequence A029998 A117461 A047005
Adjacent sequences: A101002 A101003 A101004 this_sequence A101006 A101007 A101008
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KEYWORD
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nonn,hard,more,less
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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 27 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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