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A103039
Numbers n such that 6*10^n + 5*R_n - 2 is prime, where R_n = 11...1 is the repunit (A002275) of length n.
1
2, 3, 9, 11, 12, 15, 36, 38, 41, 77, 90, 96, 132, 374, 399, 617, 1332, 1395, 1811, 2804, 4953, 5310, 16676, 29336
OFFSET
1,1
COMMENTS
Also numbers n such that (59*10^n-23)/9 is prime.
a(25) > 10^5. - Robert Price, Sep 14 2015
FORMULA
a(n) = A101532(n) + 1.
MATHEMATICA
Do[ If[ PrimeQ[(59*10^n - 23)/9], Print[n]], {n, 0, 10000}]
CROSSREFS
Sequence in context: A063257 A229492 A328970 * A140222 A272537 A121557
KEYWORD
more,nonn
AUTHOR
Robert G. Wilson v, Jan 18 2005
EXTENSIONS
a(23)-a(24) from Kamada data by Robert Price, Dec 14 2010
STATUS
approved