

A101589


Indices of primes in sequence defined by A(0) = 59, A(n) = 10*A(n1)  1 for n > 0.


1



0, 3, 7, 12, 15, 43, 438, 607, 1200, 2724, 5209, 59388, 118215, 198528
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OFFSET

1,2


COMMENTS

Numbers n such that (530*10^n + 1)/9 is prime.
Numbers n such that digit 5 followed by n >= 0 occurrences of digit 8 followed by digit 9 is prime.
Numbers corresponding to terms <= 607 are certified primes.


REFERENCES

Klaus Brockhaus and Walter Oberschelp, Zahlenfolgen mit homogenem Ziffernkern, MNU 59/8 (2006), pp. 462467.


LINKS

Table of n, a(n) for n=1..14.
Makoto Kamada, Prime numbers of the form 588...889.
Index entries for primes involving repunits.


FORMULA

a(n) = A103024(n)  1.


EXAMPLE

58889 is prime, hence 3 is a term.


PROG

(PARI) a=59; for(n=0, 1500, if(isprime(a), print1(n, ", ")); a=10*a1)
(PARI) for(n=0, 1500, if(isprime((530*10^n+1)/9), print1(n, ", ")))


CROSSREFS

Cf. A000533, A002275, A103024.
Sequence in context: A331042 A122981 A122982 * A061559 A165990 A160998
Adjacent sequences: A101586 A101587 A101588 * A101590 A101591 A101592


KEYWORD

nonn,more


AUTHOR

Klaus Brockhaus and Walter Oberschelp (oberschelp(AT)informatik.rwthaachen.de), Dec 09 2004


EXTENSIONS

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 01 2008
a(12)a(14) from Kamada data by Ray Chandler, Apr 30 2015


STATUS

approved



