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A102934 Numbers n such that 10^n + 4*R_n + 3 is prime, where R_n = 11...1 is the repunit (A002275) of length n. 1
1, 3, 4, 6, 9, 22, 28, 34, 37, 61, 82, 274, 276, 735, 1443, 2215, 2968, 3301, 3883, 3991, 5152, 8032, 8946 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

Also numbers n such that (13*10^n+23)/9 is prime.

LINKS

Makoto Kamada, Factorizations of 144...447.

Index entries for primes involving repunits.

MATHEMATICA

Do[ If[ PrimeQ[(13*10^n + 23)/9], Print[n]], {n, 0, 10000}]

CROSSREFS

Sequence in context: A107340 A173270 A018830 * A191699 A192286 A095729

Adjacent sequences:  A102931 A102932 A102933 * A102935 A102936 A102937

KEYWORD

more,nonn

AUTHOR

Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 16 2004

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Last modified February 15 16:21 EST 2012. Contains 205823 sequences.