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Search: id:A100999
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| A100999 |
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Indices of primes in sequence defined by A(0) = 97, A(n) = 10*A(n-1) - 53 for n > 0. |
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+0
1
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| 0, 16, 22, 72, 130, 472, 684, 700, 1908, 3028, 3472, 4192, 9930
(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 (820*10^n + 53)/9 is prime.
Numbers n such that digit 9 followed by n >= 0 occurrences of digit 1 followed by digit 7 is prime.
Numbers corresponding to terms <= 700 are certified primes.
a(n) = A100473(n-1) - 1.
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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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911111111111111117 is prime, hence 16 is a term.
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PROGRAM
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(PARI) a=97; for(n=0, 1000, if(isprime(a), print1(n, ", ")); a=10*a-53)
(PARI) for(n=0, 1000, if(isprime((820*10^n+53)/9), print1(n, ", ")))
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CROSSREFS
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Cf. A000533, A002275, A100473.
a(n) = A100473(n) - 1.
Sequence in context: A058901 A059756 A165338 this_sequence A070572 A006616 A166675
Adjacent sequences: A100996 A100997 A100998 this_sequence A101000 A101001 A101002
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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 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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