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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. 0
0, 30, 104, 112, 368, 1358, 6218 (list; graph; refs; listen; history; 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.

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.

FORMULA

a(n) = A103069(n) - 1. - 6218 from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 01 2008

EXAMPLE

83 is prime, hence 0 is a term.

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

Cf. A000533, A002275.

Sequence in context: A043218 A039395 A043998 * A081370 A158445 A046301

Adjacent sequences:  A101053 A101054 A101055 * A101057 A101058 A101059

KEYWORD

nonn,hard,more

AUTHOR

Klaus Brockhaus (klaus-brockhaus(AT)t-online.de) and Walter Oberschelp (oberschelp(AT)informatik.rwth-aachen.de), Nov 30 2004

EXTENSIONS

6218 from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 01 2008

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Last modified February 16 10:53 EST 2012. Contains 205904 sequences.