

A104958


Primes from merging of 2 successive digits in decimal expansion of cos(1).


2



23, 13, 97, 71, 17, 29, 97, 37, 73, 23, 31, 61, 17, 79, 67, 97, 53, 11, 47, 47, 71, 17, 17, 79, 71, 83, 89, 43, 71, 17, 73, 31, 11, 89, 97, 37, 41, 17, 73, 31, 47, 71, 17, 79, 97, 71, 11, 47, 47, 79, 23, 31, 11, 17, 79, 13, 43, 59, 43, 17, 67, 89, 59, 37, 73, 61, 43, 41, 17
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

Leading zeros are not permitted, i.e., all terms must be two digits in length.  Harvey P. Dale, Apr 20 2012
The last of the 21 2digit primes to appear is a(233) = 19.  Charles R Greathouse IV, May 13 2019


LINKS

Harvey P. Dale and Vincenzo Librandi, Table of n, a(n) for n = 1..1001
The first 15,000 digits of Cos(1) as calculated by Simon Plouffe at WorldWideSchool.org.
Eric Weisstein's World of Mathematics, Cosine Function


MATHEMATICA

Select[FromDigits/@Partition[RealDigits[Cos[1], 10, 400][[1]], 2, 1], PrimeQ[#]&&#>9&] (* Harvey P. Dale, Apr 20 2012 *)


CROSSREFS

Sequence in context: A070838 A199713 A064735 * A124601 A040508 A305943
Adjacent sequences: A104955 A104956 A104957 * A104959 A104960 A104961


KEYWORD

nonn,base


AUTHOR

Andrew G. West (WestA(AT)wlu.edu), Mar 30 2005


EXTENSIONS

Offset changed from 0 to 1 by Vincenzo Librandi, Apr 28 2013


STATUS

approved



