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A101576 Indices of primes in sequence defined by A(0) = 59, A(n) = 10*A(n-1) - 61 for n > 0. 0
0, 4, 10, 13, 61, 73, 106, 109, 120, 127, 138, 319, 2955 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

Numbers n such that (470*10^n + 61)/9 is prime.

Numbers n such that digit 5 followed by n >= 0 occurrences of digit 2 followed by digit 9 is prime.

Numbers corresponding to terms <= 319 are certified primes.

REFERENCES

Klaus Brockhaus and Walter Oberschelp, Zahlenfolgen mit homogenem Ziffernkern, MNU 59/8 (2006), pp. 462-467.

LINKS

Makoto Kamada, Factorizations of near-repdigit numbers.

EXAMPLE

522229 is prime, hence 4 is a term.

PROG

(PARI) a=59; for(n=0, 1000, if(isprime(a), print1(n, ", ")); a=10*a-61)

(PARI) for(n=0, 1000, if(isprime((470*10^n+61)/9), print1(n, ", ")))

CROSSREFS

Cf. A000533, A002275.

a(n) = A103011(n) - 1.

Sequence in context: A173793 A076270 A032821 * A179134 A103044 A114719

Adjacent sequences:  A101573 A101574 A101575 * A101577 A101578 A101579

KEYWORD

nonn,more

AUTHOR

Klaus Brockhaus (klaus-brockhaus(AT)t-online.de) and Walter Oberschelp (oberschelp(AT)informatik.rwth-aachen.de), Dec 09 2004

EXTENSIONS

2955 from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 01 2008

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Last modified February 15 03:33 EST 2012. Contains 205694 sequences.