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A102024 Indices of primes in sequence defined by A(0) = 17, A(n) = 10*A(n-1) - 3 for n > 0. 0
0, 1, 2, 4, 8, 10, 13, 31, 53, 54, 59, 152, 199, 460, 568, 839, 846, 1295, 1355, 2006, 2626, 2846, 3109, 6875, 9160 (list; graph; refs; listen; history; internal format)
OFFSET

1,3

COMMENTS

Numbers n such that (150*10^n + 3)/9 is prime.

Numbers n such that digit 1 followed by n >= 0 occurrences of digit 6 followed by digit 7 is prime.

Numbers corresponding to terms <= 846 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

167 is prime, hence 1 is a term.

PROG

(PARI) a=17; for(n=0, 1500, if(isprime(a), print1(n, ", ")); a=10*a-3)

(PARI) for(n=0, 1500, if(isprime((150*10^n+3)/9), print1(n, ", ")))

CROSSREFS

Cf. A000533, A002275.

a(n) = A102940(n) - 1.

Sequence in context: A190744 A190751 A030232 * A104197 A189792 A189782

Adjacent sequences:  A102021 A102022 A102023 * A102025 A102026 A102027

KEYWORD

nonn,hard,more

AUTHOR

Klaus Brockhaus (klaus-brockhaus(AT)t-online.de) and Walter Oberschelp (oberschelp(AT)informatik.rwth-aachen.de), Dec 28 2004

EXTENSIONS

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008

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Last modified February 14 22:22 EST 2012. Contains 205678 sequences.