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A101732
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Indices of primes in sequence defined by A(0) = 41, A(n) = 10*A(n-1) + 61 for n > 0.
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0
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OFFSET
| 1,2
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COMMENTS
| Numbers n such that (430*10^n - 61)/9 is prime.
Numbers n such that digit 4 followed by n >= 0 occurrences of digit 7 followed by digit 1 is prime.
Numbers corresponding to terms <= 924 are certified primes.
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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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EXAMPLE
| 47 is prime, hence 0 is a term.
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PROG
| (PARI) a=41; for(n=0, 1500, if(isprime(a), print1(n, ", ")); a=10*a+61)
(PARI) for(n=0, 1500, if(isprime((430*10^n-61)/9), print1(n, ", ")))
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CROSSREFS
| Cf. A000533, A002275.
a(n) = A102995(n) - 1.
Sequence in context: A041840 A012793 A015305 * A006301 A184133 A004704
Adjacent sequences: A101729 A101730 A101731 * A101733 A101734 A101735
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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 14 2004
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