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A101056 Indices of primes in sequence defined by A(0) = 83, A(n) = 10*A(n-1) - 27 for n > 0. 1
0, 30, 104, 112, 368, 1358, 6218, 105570, 150974 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Numbers n such that 80*10^n + 3 is prime.
Numbers n such that digit 8 followed by n >= 0 occurrences of digit 0 followed by digit 3 is prime.
Numbers corresponding to terms <= 368 are certified primes.
a(10) > 2*10^5. - Robert Price Aug 19 2015
REFERENCES
Klaus Brockhaus and Walter Oberschelp, Zahlenfolgen mit homogenem Ziffernkern, MNU 59/8 (2006), pp. 462-467.
LINKS
FORMULA
a(n) = A103069(n+1) - 1. - Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 01 2008
EXAMPLE
83 is prime, hence 0 is a term.
MATHEMATICA
Select[Range[0, 20000], PrimeQ[80*10^# + 3] &] (* Robert Price, Aug 19 2015 *)
PROG
(PARI) a=83; for(n=0, 1500, if(isprime(a), print1(n, ", ")); a=10*a-27)
(PARI) for(n=0, 1500, if(isprime(80*10^n+3), print1(n, ", ")))
CROSSREFS
Sequence in context: A043218 A039395 A043998 * A316362 A081370 A257891
KEYWORD
nonn,hard,more
AUTHOR
Klaus Brockhaus and Walter Oberschelp (oberschelp(AT)informatik.rwth-aachen.de), Nov 30 2004
EXTENSIONS
6218 from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 01 2008
a(8) - a(9) from Robert Price, Aug 19 2015
STATUS
approved

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Last modified March 29 08:13 EDT 2024. Contains 371265 sequences. (Running on oeis4.)