

A102994


Numbers n such that 4*10^n + 6*R_n  5 is prime, where R_n = 11...1 is the repunit (A002275) of length n.


3



1, 2, 7, 9, 14, 24, 45, 49, 73, 74, 232, 338, 397, 504, 1063, 2817, 5305, 16768, 27060
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OFFSET

1,2


COMMENTS

Also numbers n such that (14*10^n17)/3 is prime.


LINKS



FORMULA



MATHEMATICA

Do[ If[ PrimeQ[(14*10^n  17)/3], Print[n]], {n, 0, 10000}]


CROSSREFS



KEYWORD

more,nonn


AUTHOR



EXTENSIONS

Addition of a(18)a(19) from Kamada data by Robert Price, Dec 10 2010


STATUS

approved



