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 A102023 Indices of primes in sequence defined by A(0) = 13, A(n) = 10*A(n-1) + 33 for n > 0. 1
 0, 1, 2, 17, 176, 323, 387, 391, 403, 530, 1082, 12545, 22442, 54387, 72915 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Numbers n such that (150*10^n - 33)/9 is prime. Numbers n such that digit 1 followed by n >= 0 occurrences of digit 6 followed by digit 3 is prime. Numbers corresponding to terms <= 530 are certified primes. a(16) > 10^5. - Robert Price, Nov 15 2014 REFERENCES Klaus Brockhaus and Walter Oberschelp, Zahlenfolgen mit homogenem Ziffernkern, MNU 59/8 (2006), pp. 462-467. LINKS Makoto Kamada, Prime numbers of the form 166...663. FORMULA a(n) = A102939(n) - 1. - Robert Price, Nov 15 2014 EXAMPLE 163 is prime, hence 1 is a term. PROG (PARI) a=13; for(n=0, 1500, if(isprime(a), print1(n, ", ")); a=10*a+33) (PARI) for(n=0, 1500, if(isprime((150*10^n-33)/9), print1(n, ", "))) CROSSREFS Cf. A000533, A002275, A102939. Sequence in context: A046909 A041879 A011550 * A212833 A230087 A058010 Adjacent sequences:  A102020 A102021 A102022 * A102024 A102025 A102026 KEYWORD nonn,hard,more AUTHOR Klaus Brockhaus and Walter Oberschelp (oberschelp(AT)informatik.rwth-aachen.de), Dec 28 2004 EXTENSIONS a(12)-a(15) derived from A102939 by Robert Price, Nov 15 2014 STATUS approved

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Last modified October 18 00:21 EDT 2019. Contains 328135 sequences. (Running on oeis4.)