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A101077
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Indices of primes in sequence defined by A(0) = 83, A(n) = 10*A(n-1) + 43 for n > 0.
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0
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OFFSET
| 1,2
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COMMENTS
| Numbers n such that (790*10^n - 43)/9 is a prime.
Numbers n such that digit 8 followed by n >= 0 occurrences of digit 7 followed by digit 3 is prime.
Numbers corresponding to terms <= 324 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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LINKS
| Makoto Kamada, Factorizations of near-repdigit numbers.
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EXAMPLE
| 87777773 is prime, hence 6 is a term.
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MATHEMATICA
| #-1&/@(Flatten[Position[NestList[10#+43&, 83, 10000], _?PrimeQ]]) (* From Harvey P. Dale, May 20 2011 *)
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PROG
| (PARI) a=83; for(n=0, 1500, if(isprime(a), print1(n, ", ")); a=10*a+43)
(PARI) for(n=0, 1500, if(isprime((790*10^n-43)/9), print1(n, ", ")))
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CROSSREFS
| Cf. A000533, A002275.
a(n) = A103090(n) - 1.
Sequence in context: A198327 A009583 A033578 * A094952 A024526 A089581
Adjacent sequences: A101074 A101075 A101076 * A101078 A101079 A101080
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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), Nov 30 2004
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EXTENSIONS
| More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 01 2008
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