%I A102994
%S A102994 1,2,7,9,14,24,45,49,73,74,232,338,397,504,1063,2817,5305
%N 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.
%C A102994 Also numbers n such that (14*10^n-17)/3 is prime.
%H A102994 Makoto Kamada, <a href="http://homepage2.nifty.com/m_kamada/math/46661.htm">
Factorizations of 466...661</a>.
%H A102994 <a href="Sindx_Pri.html#Pri_rep">Index entries for primes involving repunits</
a>.
%t A102994 Do[ If[ PrimeQ[(14*10^n - 17)/3], Print[n]], {n, 0, 10000}]
%Y A102994 Sequence in context: A077470 A047352 A074244 this_sequence A085544 A154789
A106352
%Y A102994 Adjacent sequences: A102991 A102992 A102993 this_sequence A102995 A102996
A102997
%K A102994 more,nonn
%O A102994 1,2
%A A102994 Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 17 2005
|