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A101579 Indices of primes in sequence defined by A(0) = 53, A(n) = 10*A(n-1) + 13 for n > 0. +0
1
0, 2, 3, 8, 11, 59, 267, 288, 383, 794, 3473, 9179 (list; graph; listen)
OFFSET

1,2

COMMENT

Numbers n such that (490*10^n - 13)/9 is prime.

Numbers n such that digit 5 followed by n >= 0 occurrences of digit 4 followed by digit 3 is prime.

Numbers corresponding to terms <= 794 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

54443 is prime, hence 3 is a term.

PROGRAM

(PARI) a=53; for(n=0, 1000, if(isprime(a), print1(n, ", ")); a=10*a+13)

(PARI) for(n=0, 1000, if(isprime((490*10^n-13)/9), print1(n, ", ")))

CROSSREFS

Cf. A000533, A002275.

a(n) = A103014(n) - 1.

Sequence in context: A119197 A119185 A056922 this_sequence A041711 A127939 A041587

Adjacent sequences: A101576 A101577 A101578 this_sequence A101580 A101581 A101582

KEYWORD

nonn,more

AUTHOR

Klaus Brockhaus (klaus-brockhaus(AT)t-online.de) and Walter Oberschelp (oberschelp(AT)informatik.rwth-aachen.de), Dec 09 2004

EXTENSIONS

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

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Last modified November 30 22:12 EST 2008. Contains 150989 sequences.


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