

A171658


Primes ending with the digits 21 which are the only primes in their century.


0



155921, 5649221, 6726821, 8598221, 8825321, 9953621, 10303721, 11948021, 12117121, 14645921, 14821721, 14866421, 15275021, 17270621, 17524921, 18497321, 19193921, 19731821, 20741621, 21721621, 22170221, 23009521, 24257921, 24579221, 24919721
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

Primes of the form 100*k+21 with no other prime of the form 100*k+j for j=1 to 99 with the same k.
Thanks for the assistance and research of John Moyer. There is likely an infinite number of such primes.


LINKS



EXAMPLE

a(1)=155921 is prime and it is the only prime between 155900 and 156000.


CROSSREFS



KEYWORD

nonn,base


AUTHOR



EXTENSIONS

Definition detailed and more terms appended by R. J. Mathar, Oct 09 2010


STATUS

approved



