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A101832
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Indices of primes in sequence defined by A(0) = 33, A(n) = 10*A(n-1) + 13 for n > 0.
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0
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OFFSET
| 1,1
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COMMENTS
| Numbers n such that (310*10^n - 13)/9 is prime.
Numbers n such that digit 3 followed by n >= 0 occurrences of digit 4 followed by digit 3 is prime.
Numbers corresponding to terms <= 491 are certified primes. For number corresponding to 5567 see P. De Geest, PDP Reference Table.
a(n) = A082706(n-1) - 2. a(4) = 5567 is based on A082706.
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REFERENCES
| Klaus Brockhaus and Walter Oberschelp, Zahlenfolgen mit homogenem Ziffernkern, MNU 59/8 (2006), pp. 462-467.
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LINKS
| P. De Geest, PDP Reference Table
Makoto Kamada, Factorizations of 344...443.
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EXAMPLE
| 3444443 is prime, hence 5 is a term.
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PROG
| (PARI) a=33; for(n=0, 1500, if(isprime(a), print1(n, ", ")); a=10*a+13)
(PARI) for(n=0, 1500, if(isprime((310*10^n-13)/9), print1(n, ", ")))
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CROSSREFS
| Cf. A000533, A002275, A082706.
Sequence in context: A139187 A156330 A056253 * A046957 A174957 A174955
Adjacent sequences: A101829 A101830 A101831 * A101833 A101834 A101835
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KEYWORD
| nonn,hard,more
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AUTHOR
| Klaus Brockhaus (klaus-brockhaus(AT)t-online.de) and Walter Oberschelp (oberschelp(AT)informatik.rwth-aachen.de), Dec 20 2004
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EXTENSIONS
| 24755 from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008
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