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A101528
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Indices of primes in sequence defined by A(0) = 63, A(n) = 10*A(n-1) + 13 for n > 0.
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0
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1, 4, 5, 10, 14, 68, 89, 133, 188, 244, 266, 269, 469, 1574, 2294, 2506, 3511, 3824, 6856
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| Numbers n such that (580*10^n - 13)/9 is prime.
Numbers n such that digit 6 followed by n >= 0 occurrences of digit 4 followed by digit 3 is prime.
Numbers corresponding to terms <= 469 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
| 6444443 is prime, hence 5 is a term.
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PROG
| (PARI) a=63; for(n=0, 1000, if(isprime(a), print1(n, ", ")); a=10*a+13)
(PARI) for(n=0, 1000, if(isprime((580*10^n-13)/9), print1(n, ", ")))
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CROSSREFS
| Cf. A000533, A002275.
a(n) = A103035(n) - 1.
Sequence in context: A116930 A073119 A002257 * A119040 A135104 A131780
Adjacent sequences: A101525 A101526 A101527 * A101529 A101530 A101531
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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 06 2004
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EXTENSIONS
| More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 01 2008
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