|
|
A346028
|
|
Primes that are the first in a run of exactly 8 emirps.
|
|
2
|
|
|
334759, 9094009, 9685771, 11875307, 12503017, 19776443, 32906869, 35414443, 37376201, 70252333, 71161309, 73694129, 77454067, 93907523, 98606489, 100545637, 104827991, 112604857, 147009703, 155376791, 183766217, 187717499, 194024953, 196702423, 314716411
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
There are large gaps in this sequence because all terms need to begin with 1, 3, 7, or 9 otherwise the reversal is composite.
|
|
LINKS
|
|
|
EXAMPLE
|
a(1) = 334759 because of the 10 consecutive primes 334753, 334759, 334771, 334777, 334783, 334787, 334793, 334843, 334861, 334877 all except 334753 and 334877 are emirps and this is the first such occurrence.
|
|
MATHEMATICA
|
EmQ[n_]:=(s=IntegerReverse@n; PrimeQ@s&&n!=s);
Monitor[Do[p=Prime@k; If[MemberQ[{1, 3, 7, 9}, First@IntegerDigits@p], If[Boole[EmQ/@NextPrime[p, Range[-1, 8]]]=={0, 1, 1, 1, 1, 1, 1, 1, 1, 0}, Print@p]], {k, 10^6}], p] (* Giorgos Kalogeropoulos, Jul 27 2021 *)
|
|
PROG
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|