

A098013


Differences between consecutive primes that are twice primes.


2



4, 4, 4, 6, 6, 4, 4, 6, 6, 6, 4, 6, 4, 6, 4, 4, 4, 14, 4, 6, 10, 6, 6, 4, 6, 6, 10, 4, 4, 4, 6, 10, 6, 6, 6, 6, 4, 10, 14, 4, 4, 14, 6, 10, 4, 6, 6, 6, 4, 6, 4, 10, 10, 6, 4, 6, 4, 4, 4, 4, 6, 6, 10, 6, 6, 6, 10, 6, 6, 6, 6, 4, 10, 4, 6, 6, 4, 6, 10, 10, 6, 6, 4, 6, 4, 4, 14, 10, 10, 4, 10, 14, 4, 4, 14
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

11  7 = 4 = double 2, the first entry in the table.


LINKS

Robert Israel, Table of n, a(n) for n = 1..10000


MAPLE

R:= NULL: count:= 0:
q:= 2: p:= 3:
while count < 100 do
q:= p; p:= nextprime(p);
if isprime((pq)/2) then
count:= count+1; R:= R, pq
fi
od:
R; # Robert Israel, Jun 05 2018


MATHEMATICA

Select[Differences[Prime[Range[500]]], PrimeQ[#/2]&] (* Harvey P. Dale, Jan 31 2020 *)


PROG

(PARI) f(n) = for(x=1, n, y=prime(x+1)prime(x); if(isprime(y\2), print1(y", ")))


CROSSREFS

Cf. A100484 (twice primes).
Sequence in context: A160401 A114742 A273909 * A073229 A116446 A102126
Adjacent sequences: A098010 A098011 A098012 * A098014 A098015 A098016


KEYWORD

easy,nonn


AUTHOR

Cino Hilliard, Sep 09 2004


STATUS

approved



