

A057563


Numbers k such that the k initial decimal digits of e  2 form a prime number.


2




OFFSET

1,2


COMMENTS

a(10) > 300000 "or so" (according to S. Batalov, Jul 06 2017).  Eric W. Weisstein, Jun 10 2017


LINKS

Table of n, a(n) for n=1..9.
Titanix [Broken link]


EXAMPLE

Since e  2 = 0.71828182845904..., the first terms are:
k = 1 gives 7, which is prime.
k = 2 gives 71, which is prime.
k = 49 gives 7182818284590452353602874713526624977572470936999, which is prime.


CROSSREFS

Sequence in context: A280188 A058845 A041287 * A297819 A297989 A028479
Adjacent sequences: A057560 A057561 A057562 * A057564 A057565 A057566


KEYWORD

nonn,base,more


AUTHOR

G. L. Honaker, Jr., Oct 04 2000


EXTENSIONS

a(8) proved prime by Andrey V. Kulsha using Titanix.
a(9) from Serge Batalov, Jun 21 2017


STATUS

approved



