%I
%S 23,13,97,71,17,29,97,37,73,23,31,61,17,79,67,97,53,11,47,47,71,17,17,
%T 79,71,83,89,43,71,17,73,31,11,89,97,37,41,17,73,31,47,71,17,79,97,71,
%U 11,47,47,79,23,31,11,17,79,13,43,59,43,17,67,89,59,37,73,61,43,41,17
%N Primes from merging of 2 successive digits in decimal expansion of cos(1).
%C Leading zeros are not permitted, i.e., all terms must be two digits in length.  _Harvey P. Dale_, Apr 20 2012
%C The last of the 21 2digit primes to appear is a(233) = 19.  _Charles R Greathouse IV_, May 13 2019
%H Harvey P. Dale and Vincenzo Librandi, <a href="/A104958/b104958.txt">Table of n, a(n) for n = 1..1001</a>
%H The first <a href="http://www.worldwideschool.org/library/books/sci/math/MiscellaneousMathematicalConstants/chap14.html">15,000 digits of Cos(1)</a> as calculated by _Simon Plouffe_ at WorldWideSchool.org.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Cosine.html">Cosine Function</a>
%t Select[FromDigits/@Partition[RealDigits[Cos[1],10,400][[1]],2,1], PrimeQ[#]&&#>9&] (* _Harvey P. Dale_, Apr 20 2012 *)
%K nonn,base
%O 1,1
%A Andrew G. West (WestA(AT)wlu.edu), Mar 30 2005
%E Offset changed from 0 to 1 by _Vincenzo Librandi_, Apr 28 2013
