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Search: id:A101570
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| A101570 |
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Indices of primes in sequence defined by A(0) = 53, A(n) = 10*A(n-1) - 17 for n > 0. |
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+0
1
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| 0, 2, 18, 108, 128, 279, 386, 446, 486, 1047, 3297, 3459, 9453
(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 (460*10^n + 17)/9 is prime.
Numbers n such that digit 5 followed by n >= 0 occurrences of digit 1 followed by digit 3 is prime.
Numbers corresponding to terms <= 486 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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5113 is prime, hence 2 is a term.
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PROGRAM
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(PARI) a=53; for(n=0, 1500, if(isprime(a), print1(n, ", ")); a=10*a-17)
(PARI) for(n=0, 1500, if(isprime((460*10^n+17)/9), print1(n, ", ")))
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CROSSREFS
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Cf. A000533, A002275.
a(n) = A103005(n) - 1.
Sequence in context: A087291 A005969 A094251 this_sequence A006043 A112328 A038721
Adjacent sequences: A101567 A101568 A101569 this_sequence A101571 A101572 A101573
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KEYWORD
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nonn,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 09 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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